Saul took him that day, and would let him go no more home to his father's house.
Saul responded to Jonathan’s affection for David, and presumably David’s bravery, by keeping David with him even more than the king had done previously (1 Samuel 18:2; cf. 1 Samuel 14:52). Evidently Jonathan realized David’s gifts and God’s will for David’s life (cf. 1 Samuel 23:17), and he humbly deferred to him (1 Samuel 18:3-4).