Idolatrous Worship

[Lev. 17:3] What man soever there be of the house of Israel, that killeth an ox, or lamb, or goat, in the camp, or that killeth it out of the camp
It was forbidden to slaughter or sacrifice holy offerings outside the sanctuary forecourt. According to Jewish tradition, prior to the flood man was permitted to only eat fruits and vegetables. Before the Tabernacle was erected, a Jew was permitted to sacrifice to Hashem on any private altar that he built. Later, Hashem fixed the place for the Jews to bring their offerings and direct their hearts to Him.
The Israelites, like other people in the desert, would not make much use of animal food; and when they did kill a lamb or a kid for food, an occasion of a feast, to be eaten in company. This was what was done with the peace offerings; they should be killed publicly, and after being devoted to G-d, partaken of by the officers. This law could only be observable in the wilderness while the people were encamped with an accessible distance from the Tabernacle. The reason for it is to be found in the strong addictedness of the Israelites to idolatry at the time of their departure from Egypt; and as it would have been easy for any by killing an animal to sacrifice privately to a favorite object of worship, a strict prohibition was made against their slaughtering at home.
They is supposed by some commentators to refer to the Egyptians, so that the verse will stand thus: the children of Israel may bring their sacrifices which they (the Egyptians) offer in the open field. This law is thought to have been directed against those whose Egyptian habits led them to imitate this idolatrous practice.
Devils - literally, goats. The prohibition evidently alludes to the worship of the hire-footed kind, such as Pan, Faunus, and Saturn, who’s recognized symbol was a goat. This was a form of idolatry enthusiastically practiced by the Egyptians, particularly in the name or province of Mendes. Pan was supposed especially to preside over mountainous and desert regions, and it was while they were in the wilderness that the Israelites seem to have been powerfully influenced by a feeling to propitiate this idol. Moreover, the ceremonies observed in this idolatrous worship were extremely licentious and obscene, and the gross impurity of the rites gives great point and significance to the expression of Moses, they have gone a whoring.
Before the promulgation of the law, men worshiped whenever they pleased or pitched their tents. But after that event the rites of religion could be acceptable performed only at the appointed place of worship. This restriction with respect to place was necessary as a preventive of idolatry; for it prohibited the Israelites, when at a distance, from repairing to the altars of the heathen, which were commonly in groves or fields.
The face of G-d is often used in Scripture to denote His anger (Ps. 34:16, Rev. 6:16, Ex. 38:18.) The manner is which G-d’s face would be set against such an offender was, that if the crime were public and known, he was condemned to death; vengeance would overtake him. But the practice against which the law is here pointed was an idolatrous rite. The Zabians, or worshipers of the heavenly host, were accustomed, in sacrificing animals, to pour out the blood and eat a part of the flesh at the place where the blood was poured out (and sometimes the blood itself) believing that by between the worshipers and the deities. They, moreover, supposed that the blood was very beneficial in obtaining for them a vision of the demon curing their sleep, and a revelation of future events. The prohibition against eating blood, viewed in the light of this historic commentary and unconnected with the peculiar terms in which it is expressed, seems to have been leveled against idolatrous practices, as is still further evident from Ex. 33:25-26; 1 Cor. 10:20-21.
G-d, as the sovereign author and proprietor of nature, reserved the blood to Himself and allowed men only one use of it - in the way of sacrifices. it is the law to cover the blood of a permissible wild animal or fowl after the ritual slaughtering by placing earth both below and above it. This did not include domestic animals because their blood is sprinkled upon the altar as atonement for a sinner, making it improper to cover it.
It was customary with heathen sportsmen, when they killed any game or venison, to pour out the blood as libation to the idol of the chase. The Israelites, instead of leaving it exposed, were to cover it with dust and, by this means, were effectually debarred from all the superstitious use to which the heathen applied it.
Died of itself - ex. 22:31, Lev. 7:24, Acts 15:20. Was unclean from the moment of his discovering his fault until the evening. This law, however, was binding only on the Israelite. See Deut. 14:21.