1 Samuel 18

21And Saul said, I will give him her, that she may be a snare to him, and that the hand of the Philistines may be against him. Wherefore Saul said to David, Thou shalt this day be my son in law in the one of the twain.
26And when his servants told David these words, it pleased David well to be the king’s son in law: and the days were not expired.