Zevachim 115 - When Sacrificing Outside is Permitted

One is not liable for burning outside those parts of the sacrifices that are eaten and do not go on the Altar. One is also not liable for actions that are not the last step in the service, thus, for example, one is not liable for separating a handful from the flour-offering, but is liable for burning it. Likewise, one is not liable for receiving the blood, but is liable for throwing it on the altar.

Initially sacrificial service was done by the firstborn, and everybody was allowed to build his private altar. This is mentioned in the Torah when it says, " And Moses sent the youths of the Children of Israel, and they brought up burnt offerings ." The firstborn lost this privilege after they worshipped the Golden Calf, and the kohanim, the sons of Aaron, began to serve in their stead.

Once the Tabernacle was erected, private altars became forbidden. When the Jews came Israel, crossed the Jordan, and erected the Tabernacle at Gilgal, near Jericho, private altars again became permitted. F inally, t hey became completely prohibited after the building of the Temple in Jerusalem.

Art: Johann Wilhelm Schirmer - The Departure Of The Man To Jericho Morning C.1856