2 Samuel 18:21-25

21Then Joab said to the Cushite, “Go and tell the king what you have seen.” After bowing to Joab, the Cushite ran off.

22Ahimaaz the son of Zadok again spoke to Joab, “Whatever happens, let me go after the Cushite.” But Joab said, “Why is it that you want to go, my son? You have no good news that will bring you a reward.”

23But he said, “Whatever happens, I want to go!” So Joab said to him, “Then go!” So Ahimaaz ran by the way of the Jordan plain, and he passed the Cushite.

24Now David was sitting between the inner and outer gates, and the watchman went up to the roof over the gate at the wall. When he looked, he saw a man running by himself.

25So the watchman called out and informed the king. The king said, “If he is by himself, he brings good news.” The runner came ever closer.