Deuteronomy 12:21
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.
The verse belongs to a special law given to Israel concerning the tithe and the central place of worship, whose specific legal requirements are distinct from the lasting principle of systematic giving. It permits an Israelite living too far from the chosen place to put the divine name to kill of his own herd and flock at home and to eat in his gates whatsoever is desired.
The word soul in the verse means the physical self or appetite, describing the living person who hungers for and eats flesh. The permission to eat whatever is desired is limited to animals God had permitted as food and does not include unclean animals forbidden elsewhere in the same law.
The verse shows God permitted Israel to eat animal food, but that permission does not allow excessive indulgence like that practiced by the wicked after the flood. The sin is in eating largely, in excess and indulgence, rather than in eating animal food itself.