The controversy surrounding the dating of the Omer sacrifice revolves around both textual and polemical issues. In their effort to define the date, commentators both analyze the chronological relationship between the passages speaking of the Omer and Chag HaMatzot and question the definition of the word Shabbat, leading to three main approaches.
The Sectarians unanimously understand the word Shabbat to refer to Saturday and date the Omer sacrifice to the following day (Sunday), but disagree when this Saturday-Sunday fall. The Karaites view the two Biblical passages as referring to simultaneous time periods and thus associate the Omer offering with Chag HaMaztot itself. The Dead Sea Sect, in contrast, assumes that the Biblical text is chronological and thus have the Omer offering follow the festival, while others disconnect the two holidays totally and instead connect the Omer to the first harvest.
The Rabbinates prefer to read Shabbat as an alternative name for Yom Tov, setting the the day of the Omer sacrifice with a fixed lunar date, the 16th of Nisan.
Sunday
The word Shabbat refers to the seventh day of the week (שבת בראשית), and the Omer offering is always brought on the following day. This position subdivides regarding to which Saturday the verses refer:
Within Chag HaMatzot
The Omer is sacrificed on the morrow of the first Saturday which falls within or immediately preceding the holiday of Chag HaMatzot.
Connection to Chag MaMatzot – Since the verses regarding the Omer follow the discussion of Chag HaMatzot, all these commentators assume that the time marker "מִמׇּחֳרַת הַשַּׁבָּת" must relate to the previously mentioned holiday, and that there is chronological overlap between the two. However, they disagree regarding whether it is the Sunday of bringing the Omer or the Shabbat marked in the verse which must fall within the festival.
Sunday – The Karaites assume that it is the Omer offering itself (the day which is "מִמׇּחֳרַת הַשַּׁבָּת") which must overlap with Chag HaMatzot. Thus, the Omer offering could be brought as early as the 15th of Nisan,2 but never after the 21st.
Shabbat – The Samaritans, in contrast, maintain that the Shabbat itself must fall within the holiday. As such, one would never bring the Omer offering before the 16th, but depending on when Shabbat were to fall, one might bring it as late as the 22nd of Nisan, after the conclusion of the festival.
Evaluation of meaning of Shabbat – This understanding of Shabbat as the seventh day of the week would seem to be the simple meaning of the word, as supported by multiple verses in Torah.3
Various mentions of Shabbat – The Karaites4 point out that one of the advantages of this approach is that it is consistent in understanding the word "Shabbat" in all three of its occurrences in Vayikra 23:15-16 as referring to the seventh day of the week.5
How would one know that the Shabbat is within Chag HaMatzot? One of the main questions raised by the opponents of this position is how one is supposed to know from the verses to which Shabbat is referred,6 as it could be any Shabbat of the year! Aharon b. Levi the Karaite replies that the placement of the verses connects it to Chag HaMatzot. As mentioned above, this position assumes that there is an overlap in time between the unit of verses speaking of the holiday and those speaking of the Omer offering7 and the latter's dating is thus naturally informed by the former.8
Lack of date for Shavuot – The Karaites9 point to another advantage of this approach; it easily explains why Shavuot, unlike other holidays, is not dated in the Torah. According to them, Shavuot actually has no fixed date, only a set day of the week, and in any given year it might fall out anywhere between the 5th and 11th of Sivan.10
Significance of Sunday? A disadvantage of this position is that the Torah's normal mode of marking time is to date events to their lunar calendrical date or by an agricultural season, not by the day of the week in which they fall. Moreover, this approach must further explain what is significant about a Sunday specifically that Hashem would decide that the Omeroffering (and thus Shavuot) need fall out on that day of the week.
Two days of rest – In the Scholion to Megillat Taanit, a Boethusian tells R. Yochanan b. Zakkai that Hashem wanted the nation to rest for two consecutive days on Shavuot, which otherwise would be a short one day holiday.11
Prevent Sabbath desecration – Salmon b. Yerucham the Karaite suggests instead that Shavuot was set on Sunday to ensure that the holiday never fell on Shabbat which would be problematic for bringing a Shelamim offering.
The Karaites12 assert that the year the Israelites entered the land, Chag HaPesach fell on a Shabbat, and the Omer offering was brought on the next day ("מִמׇּחֳרַת הַפֶּסַח"),13 the 15th of Nisan, allowing the nation to eat of the new harvest on that very day. The passage in Yehoshua, thus, could support their understanding of "מִמׇּחֳרַת הַשַּׁבָּת".
Since the Samaritans do not accept Sefer Yehoshua as part of their canon they are not bothered by any contradictions from it.14
"תִּסְפׇּר לָךְ מֵהָחֵל חֶרְמֵשׁ בַּקָּמָה" – Aharon b. Yosef suggests that this time marker is equivalent to that of "מִמׇּחֳרַת הַשַּׁבָּת", with both referring to the day on which the Omer is offered. He compares the phrase to that in Divrei HaYamim II 31:10, "מֵהָחֵל הַתְּרוּמָה לָבִיא בֵית י"י" suggesting that both point to a day when a sacrifice is brought to the Mikdash.
Motivations – This reading might in part be motivated by a desire to prevent the possibility of the day of the Omer sacrifice falling on a Shabbat, necessitating reaping on Shabbat.15 Setting a fixed day of the week eliminated the need to ever have to transgress the regular laws of Shabbat.16
After Chag HaMatzot
The Omer offering is brought on the day following the first Shabbat Bereshit after the festival of Chag HaMatzot.
Meaning and mentions of Shabbat – As above, the understanding that Shabbat refers to the seventh day of the week is supported by many verses throughout Tanakh. This interpretation also allows one to explain all three appearances of the word in the same manner.
How would one know that the Shabbat is after Chag HaMatzot? According to this approach, the verses which speak of the Omer offering follow chronologically from those that precede them. As such, it is natural to assume that the Shabbat referred to is the one that falls right after Chag HaMatzot and not within it.
Dating of "מִמׇּחֳרַת הַשַּׁבָּת" – Unlike the above approach, due to the unique calendar of the Dead Sea sect17 whose year is divisible by seven, the Omer offering was always brought not only on a set day of the week but also on a set date of the month, the 26th of Nisan.18 As such, according to their calendar,19 Shavuot always falls on the 15th of Sivan.20
Lack of date for Shavuot – Since the Qumran sect does assert that the holiday of Shavuot has a set date21 it is surprising that the Torah never mentions one. They might reply that it was simply unnecessary since the law requires one to count from the Omer offering until the holiday.22
"וַיֹּאכְלוּ מֵעֲבוּר הָאָרֶץ מִמׇּחֳרַת הַפֶּסַח" – This verse in Yehoshua is difficult for this approach as it implies that the Israelites ate from the new wheat on the 15th or 16th of Nisan, while, according to Qumran, this should have been prohibited until the 26th of Nisan when the Omer was brought. They might reply that the verse is not speaking of eating of the new produce but rather the old.23
Significance of Sunday? As above, this approach might suggest that really there was no inherent significance to the day, but Hashem specifically chose a Sunday for both the bringing of the Omer and Shavuot so as to eliminate any need for desecration of Shabbat (in reaping or the sacrificing of Shelamim offerings).
After the First Harvest
The Omer is brought on the first Sunday following the initial harvest of the season.
Disconnect from Chag HaMatzot – This position disconnects the Omer offering and count from Chag HaMatzot entirely.25 It suggests that the new heading of verse 9, "וַיְדַבֵּר י"י אֶל מֹשֶׁה לֵּאמֹר" breaks the verses into two distinct units, leaving no reason why the dating of the Omer should be related to the verses speaking of Chag HaMatzot.26
"תִּסְפׇּר לָךְ מֵהָחֵל חֶרְמֵשׁ בַּקָּמָה" – According to this approach the time markers in Vayikra and Devarim complement each other. The former ("מִמׇּחֳרַת הַשַּׁבָּת") teaches which day of the week the Omer is to be brought27 while the latter ("הָחֵל חֶרְמֵשׁ בַּקָּמָה") explains when this day falls out during the year.28
Meaning and mentions of Shabbat – As above, one of the advantages of this approach is the ability to uphold the simple interpretation of the word Shabbat as the seventh day of the week in all its appearances in the passage.
Dating of "מִמׇּחֳרַת הַשַּׁבָּת" – This position, like the first approach above, assumes that there is no set date for the Omer offering. It asserts that the date is totally dependent on nature and can fall before, during, or after Chag HaMatzot.
Lack of Date for Shavuot – Since the date of the Omer offering varies from year to year based on the agricultural climate, it is easily understood why the Torah could not write a set date for Shavuot; it does not have one.
"וַיֹּאכְלוּ מֵעֲבוּר הָאָרֶץ מִמׇּחֳרַת הַפֶּסַח" – This position could maintain that the year the nation entered the land the first harvest was early and the first Sunday afterwards coincided with "מִמׇּחֳרַת הַפֶּסַח", when they brought the Omer and ate from the new grains.
Significance to Sunday – This position, even more than the others in this category, must explain why Hashem would think it necessary to choose a specific day of the week to bring the Omer. If the dating is so variable due to the changes in nature from one year to the next, why not allow the day of the week to be variable as well?29 They might agree with the suggestion above that the choice was related to ensuring that Shabbat never be violated.
Day After Yom Tov
The term Shabbat is another way of referring to Yom Tov. The Omer offering is brought on the day after the Yom Tov of Chag HaMatzot. This approach divides based on which Yom Tov is referred to:
First Yom Tov
The Omer offering follows the first Yom Tov of the festival and falls out on the 16th of Nisan.
Meaning of Shabbat – The Karaites question whether the meaning Yom Tov is a valid definition of the word Shabbat.31
The Scholion to Megillat Taanit, Lekach Tov and Ibn Ezra32 respond that many other holidays are called a "Shabbaton", pointing to Rosh HaShanah, Yom HaKippurim and Sukkot as examples.33 From these one can learn that the word Shabbaton, and hence, Shabbat, is not limited in meaning to a specific day of the week, but can refer to any Yom Tov.34
Other commentators attempt to maintain the Rabbinate dating of the Omer sacrifice as the 16th, but offer other definitions for the word Shabbat.35 Ramban proposes that it means "week", as it does in the rest of the passage. The bringing of the Omer begins a new week (for purposes of the future counting) and thus starts on the morrow of the week ending on the 15th.36 Others relate the word to "sabattu" which refers to the day of the full moon, and is thus simply another way of saying the 15th of the month.37
Why use a word with a secondary meaning? R. D"Z Hoffmann points out that the alternatives would have been ambiguous. The term "ממחרת הפסח" could refer to either the fifteenth or sixteenth of the month38 and the term "ממחרת החג" would likely be understood as referring to the 22nd of Nisan, the day after the entire festival.39
Various mentions of Shabbat – This position maintains that while the initial appearance of the word Shabbat ("וּסְפַרְתֶּם לָכֶם מִמׇּחֳרַת הַשַּׁבָּת") means Yom Tov; in the later phrases, "שֶׁבַע שַׁבָּתוֹת" and "עַד מִמׇּחֳרַת הַשַּׁבָּת הַשְּׁבִיעִת" it means week.40 The Karaites41 point to this inconsistency as a disadvantage of this approach. R. Saadia and Ibn Ezra rebut that this is an example of normal variation and literary artistry throughout Tanakh. Often, even within one verse, the text might play with words, using the same root for different understandings.42
Lack of date for Shavuot – R. Saadia asserts that no date is given for Shavuot not because it varies from year to year, but simply because it was unnecessary. Once the Torah set when to begin the count of fifty days, anyone could calculate when the festival falls.43
"וַיֹּאכְלוּ מֵעֲבוּר הָאָרֶץ מִמׇּחֳרַת הַפֶּסַח" – These commentators disagree regarding the dating of "מִמׇּחֳרַת הַפֶּסַח" and thus how this verse works with the date of bringing the Omer:
Fifteenth of Nisan – According to Ibn Ezra "מִמׇּחֳרַת הַפֶּסַח" refers to the fifteenth of Nisan,44 when eating of the new wheat was still prohibited. To solve the problem, he suggests45 that the verse speaks of eating from the old grain.46 An opinion in Yerushalmi Challah 2:1 alternatively asserts that the prohibition of "new wheat" only took effect after the conquest.47
Sixteenth of Nisan – Other exegetes48 maintain that "מִמׇּחֳרַת הַפֶּסַח" is the 16th of Nisan. Since the Pesach sacrifice is eaten on the evening of the fifteenth, the next new day is the 16th. This is equivalent to ""מִמׇּחֳרַת הַשַּׁבָּת49 when the Omer is brought and the new grain is permitted.50
"תִּסְפׇּר לָךְ מֵהָחֵל חֶרְמֵשׁ בַּקָּמָה" – This position asserts that the new harvest begins on the 16th of Nisan. The different time markers in Vayikra and Devarim are just two expressions of the same idea.
Polemical Motivations
Transgressing of Shabbat – As opposed to the Sectarians, the Sages were not bothered by the potential transgressing of Shabbat were the day of the offering of the Omer to fall on it.51 As such, they were more concerned with setting a monthly date rather than a day of the week for the offering.
Shavuot and Matan Torah – It is possible that part of the Rabbinate disagreement with the Karaites related to their desire to connect Shavuot with the revelation at Sinai. Since this was associated with the sixth of Sivan, they had an incentive to date Shavuot then.
Who Counts? If the date of the bringing of the Omer and Shavuot were variable, the fifty day count would have a practical purpose and one would assume that the calculations be done not by individuals but by the courts, as is done for the Jubilee year. Since the Sages hold that Shavuot has a set date, though, they assume the count is not purely utilitarian but rather that it must have inherent religious value. As such, they maintain that every individual must count and not just the court.
Last Yom Tov
The Omer is sacrificed on the 22nd of Nisan, the day following the last day of Chag HaMatzot.
Why the Second Yom Tov – These sources read the passage regarding the Omer as following chronologically from the previous passage53 regarding Chag HaMatzot and thus naturally assume that its dating should follow it.
Meaning of Shabbat – This position, as above, might point to other holidays which are referred to as a Shabbaton to support the possibility that a secondary meaning of the word "Shabbat" is Yom Tov.
Various mentions of Shabbat – According to this position only the first mention of Shabbat refers to Yom Tov, while the others mean "week". As above, the variation might be simply attributed to the Torah's literary artistry.
Lack of date for Shavuot – According to this approach, Shavuot always falls out on the 12th of Sivan. As above, one can explain that the Torah nonetheless leaves out the date since the fifty day count makes it superfluous.
"וַיֹּאכְלוּ מֵעֲבוּר הָאָרֶץ מִמׇּחֳרַת הַפֶּסַח" – This position might explain that Pesach in this verse refers to the entire seven day holiday and not just the day that the Pesach sacrifice was brought. If so, the "morrow of the Pesach" is the 22nd of Nisan, when the Omer is brought and new grain is permitted. No where in Tanakh, though, is the week long festival referred to as Pesach, making this a difficult read.
"תִּסְפׇּר לָךְ מֵהָחֵל חֶרְמֵשׁ בַּקָּמָה"
Morrow of a Cessation
The word Shabbat refers to something which ceased, and the Omer offering is brought on the day following this event.
Leavened bread – According to HaKetav VeHaKabbalah55 the 15th of Nisan is referred to as a Shabbat since it is a day in which one is obligated to desist from leavened bread.
The manna – Lichtenschtadt and I. Kislev assert that the Torah is referring to the future56 cessation of the manna,57 which took place on the 15th of Nisan in the year of the nation's arrival in Israel.58
Meaning of Shabbat – There is much evidence to support the idea that the root שבת refers to stopping. Its very first occurrence in Torah (Bereshit 2:3) speaks of Hashem ceasing his creative work. In noun form, too, many verses can uphold this meaning. See, for example, Shemot 15:23, 24, Shemot20:9, Shemot 31:15, and Vayikra 23:3.59
Why refer to the fifteenth in this manner?
Essence of day – According to HaKetav VeHaKabbalah, the entire essence of the first day of Yom Tov is the cessation from leavened bread. This was especially true during the year of the Exodus when leavened bread was only prohibited for that one day. HaKetav VeHaKabbalah does not explain, though, why it is only here that the first Yom Tov is so called.
Recall the manna – According to I. Kislev the Torah purposefully wants to connect the bringing of the Omer and the cessation of the manna. In fact, the entire ritual comes, in part, to commemorate the miracle and the subsequent transition from supernatural providence to natural living. Giving a calendrical date would have obscured the connection. In addition, at this point it was not yet known what specific date the people were to enter the land and stop eating manna.
Connections between the Omer and the Manna
Date – By dating one event to the other, the Torah connects them.
Amount – The specific measure of an omer's worth of the harvest recalls the omer's worth of manna that was allotted to each Israelite each day.
Food source – While the harvest focuses on man's natural food supply, the manna represents Hashem's supernatural source of sustenance. The cessation of the latter is what led to man's harvesting.
Why is the cessation of the manna worthy of commemoration? Throughout the forty years in the desert the manna served as a constant reminder of God's providence. Its absence on Shabbat and the provision of a double portion the day before reinforced the nation's dependence on God. Upon entry to the land and the transition to natural providence with the cessation of the manna, the likelihood that the nation would forget its reliance on God grew. Thus, at the moment of harvest, when man is most likely to attribute his success to himself, the Torah commands to bring the Omer sacrifice and remember the messages of the manna.
Why commemorate the event only the day afterwards? Kislev suggests that this was a practical decision. If the commemoration took place on the actual day of cessation, Nisan 15, the meaning of the day would be obscured by the celebration of the Yom Tov of Chag HaMatzot
"וַיֹּאכְלוּ מֵעֲבוּר הָאָרֶץ מִמׇּחֳרַת הַפֶּסַח" – Kislev understands "מִמׇּחֳרַת הַפֶּסַח" to refer to the 15th and suggests that in the year of entry the nation did eat from the new grain already on that day, because that year it was the cessation of the manna itself that permitted the eating. Only in future years did one need to wait for the bringing of the Omer, which is only a commemoration of this original event (a day late).60
Lack of date for Shavuot – It is possible that at the time of the giving of the command, the exact entry date into the land (and the related ceasing of supernatural sustenance) was unknown. Thus no set date could be given for either the bringing of the Omer or Shavuot.