Exegetes differ in their understanding of the scope of the ban on private altars in the land of Israel. Some view it as a direct continuation of the similar prohibition in the wilderness which was integrally related to the struggle against idolatry. Thus, the students of R. Yishmael maintain that the injunction began immediately after the construction of the Mishkan and never ceased except for a brief period during which the Tabernacle did not exist or was inaccessible. R. Shimon b. Yochai, in contrast, suggests that the original proscription was limited to the circumstances in the wilderness and was discontinued upon entry into the Land of Israel. He suggests that the prohibition was renewed only much later, when the Beit HaMikdash was built, as Hashem's choosing of a permanent home precluded worship elsewhere. Finally, the majority opinion in Chazal (and of many commentators in their wake) distinguishes between the peaceful eras of Shiloh and Yerushalayim and the unrestful periods of Gilgal, Nov, and Givon. It maintains that centralization of worship could be expected of the nation only when they were living in relative security and could travel freely.
Immediately After the Conquest
Altars for individual sacrifice were permanently prohibited as soon as the Israelites inherited the land of Israel in the time of Yehoshua.
- Prevent idolatry – This position might connect the prohibition to the practice's similarity to idolatrous worship.5 If so, it is only logical that there should be no significant periods of permissibility.6
- Limit sacrifices to Hashem's dwelling – Alternatively, this approach might posit that the establishment of the Tabernacle itself precluded worship outside of its domain, and the ban began with its completion and continued thereafter.7
- Site of Shiloh – R. Yishmael's school asserts that both terms refer to the city Shiloh, the site in which the nation rested ("הַמְּנוּחָה") after the conquest and in which the inheritances ("הַנַּחֲלָה") were given out.
- Era of Peace – According to Yefet, the terms do not refer to a specific place but to the era of peace and inheritance which commenced following the conquest.9
- הוראת שעה – The Bavli explicitly discusses only the case of Manoach, suggesting that he was acting in accordance with a one time command (הוראת שעה)14 which overrode the prohibition against private altars. This position would likely maintain that all the other cases of private altars were similarly mandated by Hashem as one time exceptions to the rule.15
- Special dispensations in Hashem's presence – Yefet suggests that the ban on private altars had several general exceptions which are derived from Shemot 20:20.16 He interprets the verse stating that one can build a stone or earthen altar "בְּכָל הַמָּקוֹם אֲשֶׁר אַזְכִּיר אֶת שְׁמִי" ("in any place where I will mention My name") to refer to any of the following three cases:
Only Once the Beit HaMikdash was Built
Private altars were completely permitted until the period of the monarchy. Only with the building of the Beit HaMikdash were they no longer allowed.
Private altars were prohibited both when the Mishkan was in Shiloh and after the Beit HaMikdash was established, but were permitted during the conquest and while the Mishkan was located in Nov and Givon.
- Presence of a complete Tabernacle – R. Yosa in the Yerushalmi Megillah34 and the Meshekh Chokhmah posit that only when the Mishkan/Mikdash contained the Ark, was it considered to be the exclusive dwelling place of Hashem.35 Thus, the prohibition of private altars existed only during the eras of Shiloh and Yerushalayim when the Ark resided together with the main sacrificial altar.36 However, when the Mishkan was in Gilgal, Nov, and Givon, the Ark was separate from the rest of the Tabernacle and the Divine presence was more diffused, thus allowing for the existence of additional outside altars.
- Permanent structure – Only the building of a permanent dwelling for Hashem mandates an exclusive worship site,37 while temporary housing is not so different from the temporary altars built by private individuals.38 Since each of the Tabernacle in Shiloh and the Beit HaMikdash existed for about 400 years,39 they were accompanied by a prohibition of other altars. Other sites of the Tabernacle, though, were much more temporary, and thus not exclusive.
- One God, one temple – R"Y Bekhor Shor relates the prohibition to a fear of idolatry,40 while Ralbag and R. D"Z Hoffmann assert that the unitary nature of Hashem mandates a single place of worship.41 Although according to both of these reasons, the prohibition should have theoretically applied at all times, R. D"Z Hoffmann asserts that this was not feasible because of technical considerations. Centralization of worship could take place only in times of peace, when wars would not impede the nation from traveling to/constructing a permanent site of worship. Thus, only during the relatively quiet era of Shiloh and the peaceful reigns of the Davidic monarchy, was the nation expected to sacrifice exclusively in the Mikdash.42
- Shiloh and Yerushalayim – R. D"Z Hoffmann claims that the verse can refer to the periods of both Shiloh and Yerushalayim. Though full security was only attained with the Davidic monarchy, there was relative peace in the period after the conquest as attested to by the very name Shiloh, or tranquility.48 Both these eras are described in later Biblical verses as periods during which Hashem gave the nation rest from their enemies, using language almost identical to that of Devarim 12.49 The periods in between, in contrast, were filled with wars against the Philistines and other enemies.
- Only Yerushalayim – Rashi, in contrast, asserts that this verse refers only to the era of David and Shelomo, in which full peace and security were attained. According to him, Shiloh is referred to only in the earlier verses (which make no mention of security).50
- In Gilgal – The Sifre, Rashi, and Ralbag maintain that the phrase refers to the time period mentioned in Devarim 11:31 immediately after the crossing of the Jordan. Thus, the verse is contrasting the era of the wilderness when one brought all sacrifices to the Mishkan, with the period of Gilgal when one could bring what one pleased on private altars.51 Accordingly, the verse would read: "You will not [need to] do [in Gilgal] as we do today [in the wilderness, where all sacrifices are brought to the Mishkan], [but rather] each man can do as he pleases."52
- During the fortieth year in the wilderness
- Private altars permitted in the fortieth year – R. D"Z Hoffmann suggests that after the conquest of the eastern side of the Jordan, the original wilderness prohibition on private altars was nullified.53 Thus, Moshe is contrasting the practice of the nation in the fortieth year who "did as they pleased" and established private altars at will, with the renewed prohibition in Israel, where they would no longer be able to do so.
- Land-based commandments not obligatory in the wilderness – R. Yosef Bekhor Shor explains54 that the verse is not speaking about private altars at all, but is rather contrasting the obligations of the period of the wilderness when the nation was not yet required to fulfill the commandments that were conditional upon entry to the land (i.e. tithes and annual pilgrimages), with those of the era in Israel when all commandments would be in effect.
- Altars in Sefer Yehoshua – The anger of the nation at the 2½ tribes for building an altar on the Jordan might support the idea that (at this time) when the Tabernacle was in Shiloh, such private altars were forbidden.
- Altars in Sefer Shofetim – The altars built by Gidon, Manoach, and the nation (both in Bokhim and in Beit El) are problematic, as these were all constructed in the era when private altars were not allowed. Bavli Zevachim asserts that Manoach acted upon a one time commandment (הוראת שעה).55 This explanation can be used to solve the other cases as well.56 Alternatively, the Meshekh Chokhmah asserts that while the nation was in Bokhim and Beit El, the ark was temporarily outside of the Mishkan,57 and this allowed for the building of private altars.58
- Altars in Sefer Shemuel – The altars of Shaul and Shemuel are not an issue as they were built during the period after the destruction of Shiloh when private altars were allowed.59
- Altars of Sefer Melakhim – Eliyahu's altar on Mt. Carmel can be explained as a one-time exception (הוראת שעה).