21 Do not eat anything you find already dead. You may give it to the foreigner residing in any of your towns, and they may eat it, or you may sell it to any other foreigner. But you are a people holy to the LORD your God. Do not cook a young goat in its mother’s milk.

Read Deuteronomy 14:21 Using Other Translations

Ye shall not eat of any thing that dieth of itself: thou shalt give it unto the stranger that is in thy gates, that he may eat it; or thou mayest sell it unto an alien: for thou art an holy people unto the LORD thy God. Thou shalt not seethe a kid in his mother's milk.
"You shall not eat anything that has died naturally. You may give it to the sojourner who is within your towns, that he may eat it, or you may sell it to a foreigner. For you are a people holy to the LORD your God. "You shall not boil a young goat in its mother's milk.
“You must not eat anything that has died a natural death. You may give it to a foreigner living in your town, or you may sell it to a stranger. But do not eat it yourselves, for you are set apart as holy to the LORD your God. “You must not cook a young goat in its mother’s milk.