Deuteronomy 21 begins with an unsolved homicide. Bloodshed polluted the land, so the elders measured to the nearest city. Its elders broke the neck of a heifer in an untilled valley, washed their hands over it, declared that their hands had not shed this blood, and prayed, Forgive, Yahweh, your people Israel, whom you have redeemed. Communities bear responsibility for justice even when the guilty party is hidden.
Several family laws follow, written for a world of war and polygamy. A captive woman could become a wife only after a month of mourning and could never be sold or treated as a slave. A man with two wives could not transfer the firstborn's double portion out of favoritism. A persistently rebellious son, a glutton and drunkard, was brought by both parents to the elders and faced death. These laws limited abuse and upheld the family, though Jesus later showed God's original design for marriage (Matthew 19:4-8).
The final law commands that a body hanged on a tree be buried the same day, for he who is hanged is accursed of God. Paul applies this to Jesus: Christ redeemed us from the curse of the law, having become a curse for us (Galatians 3:13). The tree of curse became the place of our redemption.