20 Now Saul's daughter Michal loved David; and they told Saul, and the thing pleased him. 21 Saul thought, "Let me give her to him, that she may be a snare for him, and that the hand of the Philistines may be against him." Therefore Saul said to David a second time, "You shall now be my son-in-law." 22 And Saul commanded his servants, "Speak to David in private and say, 'Behold, the king has delight in you, and all his servants love you; now then become the king's son-in-law.'" 23 And Saul's servants spoke those words in the ears of David. And David said, "Does it seem to you a little thing to become the king's son-in-law, seeing that I am a poor man and of no repute?" 24 And the servants of Saul told him, "Thus and so did David speak." 25 Then Saul said, "Thus shall you say to David, 'The king desires no marriage present except a hundred foreskins of the Philistines, that he may be avenged of the king's enemies.'" Now Saul thought to make David fall by the hand of the Philistines. 26 And when his servants told David these words, it pleased David well to be the king's son-in-law. Before the time had expired, 27 David arose and went, along with his men, and killed two hundred of the Philistines; and David brought their foreskins, which were given in full number to the king, that he might become the king's son-in-law. And Saul gave him his daughter Michal for a wife.
Matthew Henry's Commentary on 1 Samuel 18:20-27
Commentary on 1 Samuel 18:12-30
(Read 1 Samuel 18:12-30)
For a long time David was kept in continual apprehension of falling by the hand of Saul, yet he persevered in meek and respectful behaviour towards his persecutor. How uncommon is such prudence and discretion, especially under insults and provocations! Let us inquire if we imitate this part of the exemplary character before us. Are we behaving wisely in all our ways? Is there no sinful omission, no rashness of spirit, nothing wrong in our conduct? Opposition and perverseness in others, will not excuse wrong tempers in us, but should increase our care, and attention to the duties of our station. Consider Him that endured contradiction of sinners against himself, lest ye be weary and faint in your minds, Hebrews 12:3. If David magnified the honour of being son-in-law to king Saul, how should we magnify the honour of being sons to the King of kings!