21 Then Joab said to the Cushite, "Go, tell the king what you have seen." The Cushite bowed before Joab, and ran. 22 Then Ahimaaz the son of Zadok said again to Joab, "Come what may, let me also run after the Cushite." And Joab said, "Why will you run, my son, seeing that you will have no reward for the news?" 23 "Come what may," he said, "I will run." So he said to him, "Run." Then Ahimaaz ran by the way of the plain, and outran the Cushite. 24 Now David was sitting between the two gates, and the watchman went up to the roof of the gate by the wall, and when he lifted up his eyes and looked, he saw a man running alone. 25 The watchman called out and told the king. And the king said, "If he is alone, there is news in his mouth." And he drew nearer and nearer.
Matthew Henry's Commentary on 2 Samuel 18:21-25
Commentary on 2 Samuel 18:19-33
(Read 2 Samuel 18:19-33)
By directing David to give God thanks for his victory, Ahimaaz prepared him for the news of his son's death. The more our hearts are fixed and enlarged, in thanksgiving to God for our mercies, the better disposed we shall be to bear with patience the afflictions mixed with them. Some think David's wish arose from concern about Absalom's everlasting state; but he rather seems to have spoken without due thought. He is to be blamed for showing so great fondness for a graceless son. Also for quarrelling with Divine justice. And for opposing the justice of the nation, which, as king, he had to administer, and which ought to be preferred before natural affection. The best men are not always in a good frame; we are apt to over-grieve for what we over-loved. But while we learn from this example to watch and pray against sinful indulgence, or neglect of our children, may we not, in David, perceive a shadow of the Saviour's love, who wept over, prayed for, and even suffered death for mankind, though vile rebels and enemies.