Hashem promises that the produce from the sixth year will feed the nation for three full years. This position subdivides regarding the situation spoken of in the verses:
Shemittah Followed by Yovel
The verses speak of a case in which Shemittah is followed by the Jubilee Year. Since there are then two consecutive years in which sowing is prohibited, Hashem promises that the food planted in the sixth year will sustain the people for three entire years.
Context – This reading is supported by the location of these verses after the discussion of the Jubilee year, rather than after the laws of Shemittah.
"וְעָשָׂת אֶת הַתְּבוּאָה לִשְׁלֹשׁ הַשָּׁנִים" – This position can understand the phrase "לִשְׁלֹשׁ הַשָּׁנִים" simply, to mean a period of 36 months. In the sixth year enough produce will be harvested to nourish the people for three years.1
"עַד הַשָּׁנָה הַתְּשִׁיעִת... תֹּאכְלוּ יָשָׁן" – According to this position, this verse means that the old grain will be eaten through (עד ועד בכלל) the ninth year.2
Exceptional Case – R. Hoffmann questions this position, claiming that it is odd that the Torah would be concerned only with the exceptional case of Shemittah followed by a Jubilee Year rather than the worries brought by every Shemittah year. Abarbanel, however, claims that there is no need to discuss the regular scenario since there might be many years when there is a crop failure which necessitates one year's harvest to subsist for two. Thus, it is specifically the severe scenario that the verses must address.
"מַה נֹּאכַל בַּשָּׁנָה הַשְּׁבִיעִת" – It is unclear why the nation should be questioning "מַה נֹּאכַל בַּשָּׁנָה הַשְּׁבִיעִת" since they should have sufficient food for the seventh year from the previous year's crops;3 it is only in the eighth year that food might be scarce. Commentators offer several possible re-readings of the verse:
Ramban and Abarbanel suggest to rearrange the order of the verse (לסרס המקרא) so that it reads, "And if you say in the seventh year, "what shall we eat [in the eighth year]".
Abarbanel alternatively suggests to repunctuate the verse, putting a pause after the words, "מַה נֹּאכַל" rather than after "בַּשָּׁנָה הַשְּׁבִיעִת".4 As such, the verse reads, "If you say, 'What shall we eat? [After all] in the seventh year we may not sow or harvest!?'"
R. Wesseley, instead, suggests that the people are asking, "how will we eat [in peace] in the seventh year knowing that we won't be sowing or gathering [for the next year]?
"וּזְרַעְתֶּם אֵת הַשָּׁנָה הַשְּׁמִינִת" – This phrase is difficult for this position as it suggests that the people will be sowing in the eighth year, while these sources maintain that the eighth year is a Jubilee year when this is forbidden:
This position might assert that the Jubilee year is not counted among the years of the Shemittah cycle, and thus, the eighth year of the verse refers to the year after Yovel.
Abarbanel
R"Y Bekhor Shor, Ramban,5 and R. Wessely suggest that in reality the verses are addressing both the regular scenario and the more exceptional Yovel year. The phrase "וּזְרַעְתֶּם אֵת הַשָּׁנָה הַשְּׁמִינִת" goes back to a normal cycle in which sowing is permitted in the eighth year.
Every Shemittah
The Shemittah year begins in Nissan, during the harvest season. As such, during every Shemittah cycle, no food is sown already in the second half of the sixth year, requiring the fifth year to make enough food to last for the entire sixth, seventh and eighth years.
Hashem blesses the nation that the crops planted in the beginning of the sixth year will suffice to nourish them across parts of three years of the shemittah cycle: during the second half of the sixth year, the entire seventh year, and the first half of the eighth year.
