After the destruction of the First Temple in 586 BCE, the Jewish people were given permission to return to their land and rebuild the Second Temple by Cyrus the Great of Persia seventy years later. The Gemara on today’s daf (=page) discusses how the returnees knew what to do.
With regard to the placement of the Temple itself, it is essential that the building was in the proper place. Nevertheless, the Gemara suggests that it was a simple matter of locating the original foundation of the First Temple and building in that place. The altar also had to be in a specific place, but it had no foundations upon which to base the plans for it. How did they know where it was to be placed?
Several theories are related by the Gemara, ranging from prophetic visions, to physical evidence of the ashes of the Binding of Issac — which is understood to have taken place on Mount Moriah (actually the ashes of the ram that was sacrificed instead of Issac). Another suggestion is that is was based on smell, and the place of the altar had the smell of the burning of the meat of the sacrifices — as opposed to the smell of incense that was found elsewhere on the mountain.
- One described the form, shape and size of the altar
- One testified about its place in the Temple
- One brought the ruling that allowed the sacrificial service to begin on the altar even before the Temple was completed.
Some commentaries point out that the Gemara does not say that these prophets used their prophetic abilities sincehalakhah cannot be decided based on prophecy (see the Rambam‘s Mishneh Torah, Hilkhot Yesodei ha-Torah). TheTiferet Yisrael, however, argues that with regard to the details of the laws of the Temple, prophecy is essential, since thenavi attests that the Temple was prepared by King David with Heavenly direction (see Divrei ha-Yamim I:28:19).