If the place which the Lord thy God hath chosen to put his name there be too far from thee, then thou shalt kill of thy herd and of thy flock, which the Lord hath given thee, as I have commanded thee, and thou shalt eat in thy gates whatsoever thy soul lusteth after. (Deuteronomy 12:21)
During the wanderings in the wilderness the sanctuary was near to the people; therefore all flesh was eaten in the presence of God (Lev. 17:3, 4). With the enlargement of the borders of the nation it would be a difficult and expensive journey for many to appear at one place, no matter where it was appointed. The distance to a central place of worship would for most of the people be too far away for reasonable convenience.
Thy gates.
The people might eat of their flocks and herds at home. An elaboration of vs. 15 and 16, and a modification of the strict injunction against so doing while they were in the wilderness.