2 Samuel 18:20

"Then said Ahimaaz the son of Zadok, "Let me run and carry tidings to the king that the Lord has delivered him from the power of his enemies." And Joab said to him, "You are not to carry tidings today; you may carry tidings another day, but today you shall carry no tidings, because the king's son is dead." Then Joab said to the Cushite, "Go tell the king what you have seen." The Cushite bowed before Joab and ran. Then Ahimaaz the son of Zadok said again to Joab, "Come what may, let me also run after the Cushite." And Joab said to him, "Why will you run, my son, seeing you have no reward for the tidings"? "Come what may," he said, "I will run." So he said to him. "Run." Then Ahimaaz ran by way of the plain, and outran the Cushite."

David had executed the messenger who brought him the news of Saul's death, and also the ones who brought him the news of the death of Ishbosheth (2 Samuel 1:15-16; 4:5-12), and Joab wanted to spare Ahimaaz the danger he would encounter if he brought David the news of the death of his son Absalom. For that reason, he sent a negro slave, called here "The Cushite" with the news that he knew would break the king's heart. "Cushite was not the man's personal name, but signifies that he was an Ethiopian, that is, a negro slave in the service of Joab."[25]