Saul’s jealousy of David turned murderous. He first tried to have David killed by the hand of the Philistines by asking David to become his son-in-law. The king offered his daughter in return for David's military service. David, in humility, refused, and Saul's daughter was given to another (1 Samuel 18:17–19). Saul's other daughter, Michal, was in love with David, so Saul asked again. David again refused due to his lack of wealth and inability to afford the bride price for the daughter of a king. Saul asked for a hundred Philistine foreskins, hoping David would be slaughtered by the enemy. When David killed two hundred Philistines, doubling the required payment, Saul realized he was outmatched, and his fear of David increased (1 Samuel 18:17–29). Jonathan and Michal warned David of their father's murderous intent, and David spent the next years of his life fleeing from the king. David wrote several songs during this time, including Psalms 57, 59, and 142.