Then David sent messengers to Saul’s son Ish-Bosheth. He ordered them to say, “Give me my wife Michal. She was promised to me. I paid for her the price that was demanded. I paid for her with the skins of 100 circumcised Philistines.”
David and his men went out and killed 200 Philistines. They circumcised the Philistines. Then David brought back all the skins. They counted out the full number and gave them to the king. By doing that, David could become the king’s son-in-law. So Saul gave David his daughter Michal to be his wife.