Exodus 23:19 in the World English Bible
You shall bring the first of the first fruits of your ground into the house of the LORD your God. “You shall not boil a young goat in its mother’s milk.
Context
18 Thou shalt not offer the blood of my sacrifice with leavened bread; neither shall the fat of my sacrifice remain until the morning.
19 The first of the firstfruits of thy land thou shalt bring into the house of the LORD thy God. Thou shalt not seethe a kid in his mother’s milk.
20 Behold, I send an Angel before thee, to keep thee in the way, and to bring thee into the place which I have prepared.