8 And Saul was very wroth, and that saying was evil in his sight; and he said, They have ascribed to David ten thousands, but to me they have ascribed the thousands; and [what] is there more for him but the kingdom? 9 And Saul eyed David from that day and forward.
Matthew Henry's Commentary on 1 Samuel 18:8-9
Commentary on 1 Samuel 18:6-11
(Read 1 Samuel 18:6-11)
David's troubles not only immediately follow his triumphs, but arise from them; such is the vanity of that which seems greatest in this world. It is a sign that the Spirit of God is departed from men, if, like Saul, they are peevish, envious, suspicious, and ill-natured. Compare David, with his harp in his hand, aiming to serve Saul, and Saul, with his javelin in his hand, aiming to slay David; and observe the sweetness and usefulness of God's persecuted people, and the barbarity of their persecutors. But David's safety must be ascribed to God's providence.