17:1-9 All the cattle killed by the Israelites, while in the wilderness, were to be presented before the door of the tabernacle, and the flesh to be returned to the offerer, to be eaten as a peace-offering, according to the law. When they entered Canaan, this only continued in respect of sacrifices. The spiritual sacrifices we are now to offer, are not confined to any one place. We have now no temple or altar that sanctifies the gift; nor does the gospel unity rest only in one place, but in one heart, and the unity of the Spirit. Christ is our Altar, and the true Tabernacle; in him God dwells among men. It is in him that our sacrifices are acceptable to God, and in him only. To set up other mediators, or other altars, or other expiatory sacrifices, is, in effect, to set up other gods. And though God will graciously accept our family offerings, we must not therefore neglect attending at the tabernacle.

8, 9. Whatsoever man … offereth … And bringeth it not unto the door of the tabernacle—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 heathen, which were commonly in groves or fields.