And thou shalt say unto them, Whatsoever man there be of the house of Israel, or of the strangers which sojourn among you, that offereth a burnt offering or sacrifice,
Whatsoever man ... offereth ... and bringeth it not unto the door. Before the promulgation of the law, men worshipped wherever they pleased or pitched their tents. But after that event the rites of religion could be acceptably 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 pagan, which were commonly in groves or fields. But in special circumstances a relaxation of this law seems to have been permitted; and in point of fact, several instances are recorded in the later historical books of sacrifices being offered elsewhere without any imputation of blame or expression of censure even by prophets themselves (Judges 2:5; 1 Samuel 7:17; 1 Samuel 9:12; 1 Kings 18:19; 1 Kings 18:32).
In early times, however, especially after the exodus, when Egyptian associations possessed a powerful influence over the minds of the people, this law was imperatively necessary as well as stringently enforced. 'Considering the propensity to idolatry which the Israelites brought with them from Egypt, there was urgent need to take care lest, when any one killed such animals as were clean and usual for sacrifices, he should be guilty of superstitiously offering them to an idol. This precaution was the more reasonable, because in ancient times it was so very common to make an offering of the flesh it was intended to eat. And hence, arose a suspicion, not very unreasonable, that whoever killed animals usually devoted to the altar, offered them of course: and therefore Moses enjoined them not to kill such animals otherwise than in public, and to offer them all to the true God; that so it might be out of their power to make them offering to idols, by slaughtering them privately and under the pretence of using them for food (Michaelis, 'Commentary,' art. 244).