Matthew Henry on 1 Samuel 18:12–end
Saul had now, in effect, proclaimed war with David. He began in open hostility when he threw the javelin at him. Now we are here told how his enmity proceeded, and how David received the attacks of it.
I. See how Saul expressed his malice against David. 1. He was afraid of him, Sa1 18:12. Perhaps he pretended to be afraid that David would do himself mischief, to force his way to the crown. Those that design ill against others are commonly willing to have it thought that others design ill against them. But David's withdrawal (Sa1 18:11) was a plain evidence that he was far from such a thought. However, he really stood in awe of him, as Herod feared John, Mar 6:20. Saul was sensible that he ha…
Read the whole note in the consoleJamieson-Fausset-Brown on 1 Samuel 18:20
Michal Saul's daughter loved David--This must have happened some time after.
they told Saul, and the thing pleased him--Not from any favor to David, but he saw that it would be turned to the advancement of his malicious purposes, and the more so when, by the artful intrigues and flattery of his spies, the loyal sentiments of David were discovered.
Adam Clarke on 1 Samuel 18:21
That she may be a snare to him - Saul had already determined the condition on which he would give his daughter to David; viz., that he should slay one hundred Philistines: this he supposed he would undertake for the love of Michal, and that he must necessarily perish in the attempt; and thus Michal would become a snare to him.
John Gill on 1 Samuel 18:24
And the servants of Saul told him, saying, on this manner spake David. Such and such words were spoken by him, to this purpose; the sum and substance of them were expressive of his unworthiness to be a king's son-in-law, and of his inability to bring a dowry suitable to her quality.
Keil & Delitzsch on 1 Samuel 18:17–end