Question: In Genesis, when Noah comes out of the ark (Gen 8:18-20) he immediately builds an altar to the Lord. I was just wondering how he knew to do this…. this seems to me to be the first time in scripture an altar is built… was this common practice? I was curious to when this practice originated?

Answer: Yes, you’re right. This is the first time in the Bible that altar-building is mentioned. Some regard Noah as “the pioneer of all the altar-builders of the Bible.” (J.H. Hertz, The Pentateuch and Haftorahs). However, we have a tradition from Maimonides (Rambam), that Noah built his altar at the same location and possibly with the same materials used by Cain and Abel and their father before them, Adam, in the altars that they used, on the Temple Mount, or Mount Moriah, in what became Jerusalem. (Maimonides’ Mishneh Torah, Hilchot Beit HaBechirah 2:2). But building a mizbeyach/altar to make a burnt offering for sacrifice – remembering that burnt offerings, where the whole offering is completely burnt and destroyed, seem to have been the only kind of offerings known before the Revelation of the Torah at Mt. Sinai – strikes me as simply practical. Without some sort of frame or structure used to hold the burning offering, as if one just tried to burn it on the ground, as over a campfire, it would be extremely difficult to burn the whole offering without having to keep going back and shoving it around to make sure the whole thing gets consumed. An altar, a frame or structure, would make the job much easier, and certainly more dignified.

Michael Dallen, author of The Rainbow Covenant: Torah and the Seven Universal Laws