Onan knew that the offspring wouldn’t be his; and when he went in to his brother’s wife, he spilled his semen on the ground, lest he should give offspring to his brother.
If brothers dwell together, and one of them dies and has no son, the wife of the dead shall not be married outside to a stranger. Her husband’s brother shall go in to her, and take her as his wife, and perform the duty of a husband’s brother to her.
Moreover, Ruth the Moabitess, the wife of Mahlon, I have purchased to be my wife, to raise up the name of the dead on his inheritance, that the name of the dead may not be cut off from amongst his brothers and from the gate of his place. You are witnesses today.”