John Gill Bible Commentary

And Saul said to David,.... Not in friendship and good will to him, but designing to lay a snare for him: behold, my eldest daughter Merab, her will I give thee to wife; most interpreters understand it, that he was obliged to this by promise, on account of David's slaying Goliath, Sa1 17:25; but Abarbinel is of another mind, and he rightly observes, that the words referred to are not the words of Saul, but of the men of Israel, who might suppose what the king would do; or if they heard anything like it spoken by Saul, it was only in a hyperbolical way, signifying he did not care what he gave, and what he parted with, to the man that killed the Philistine, but was not strictly bound to this particular thereby; nor did David ever claim such promise, nor did Saul think himself bound to do it, but proposes it as an instance of his great kindness and favour, as he pretended, and therefore expected great returns for it, as follows: only be thou valiant for me, and fight the Lord's battles: he knew he was a valiant man, and ready enough to fight; but he expected that in consideration of such a favour, and such high honour as this, that he would exert himself in an extraordinary manner, and engage in hazardous attempts, and show himself worthy to be the son of a king, in the defence of him and of his country, and for the glory of the God of Israel; all this he suggests, when his view was, that he should expose his life to such danger, that it might be hoped it would be taken away: for Saul said; not openly and verbally, but in his heart; he thought within himself: let not mine hand be upon him; he had attempted to lay hands on him, or to kill him with his own hands, but now he thought better, and consulted his credit among the people: but let the hand of the Philistines be upon him; he hoped by these means that he would fall by their hands at the head of his troop, while he was displaying his valour, and hazarding his life for the good of his king and country; what Saul contrived proved his own case, he died in battle with the Philistines, Sa1 31:4.