"Do not cook a young goat in it's mother's milk" (Exodus 34:26)
Though most biblical scholars says that it is God's commandment telling the Israelites not to mimic the pagan ways of sacrificing kid's meat in its mother's milk. There are other interpretations still.
Some says it is a commandment about compassion.
Some says it is a commandment about cruelty.
Some says it is a commandment that tells us not to kill a child with it's parent's sin.
They are all good interpretations, though...
But I would like to think it this way...
The young goat is Jesus and the Mother is God and the milk is their Glory.
God, from the very beginning knows that later on, because of man's sins, He will have to sacrifice his only begotten son to redeem the world. And God knows that Jesus, when He walks the earth, He will be rejected and will not be recognized as the son of God. So this means that we should not reject Jesus from the glory of God. We should not kill the divinity of Jesus just because He became a man on earth. Remember no one goes to God without going to Jesus first. This commandment (in my opinion) is for other religions that stating that Jesus was just a mere prophet and not a messiah, not the son of God at all. God wants us to acknowledge Jesus as also a God because He is the son of God, He is with God... remember they are three (father, son, and holy ghost). God is so good that He made this commandments a long time ago even before he sends Jesus here on earth.
Just a thought.