Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[294] AFTER this, when the country was greatly afflicted with a famine, David besought God to have mercy on the people, and to discover to him what was the cause of it, and how a remedy might be found for that distemper. And when the prophets answered, that God would have the Gibeonites avenged whom Saul the king was so wicked as to betray to slaughter, and had not observed the oath which Joshua the general and the senate had sworn to them: If, therefore, said God, the king would permit such vengeance to be taken for those that were slain as the Gibeonites should desire, he promised that he would be reconciled to them, and free the multitude from their miseries. As soon therefore as the king understood that this it was which God sought, he sent for the Gibeonites, and asked them what it was they should have; and when they desired to have seven sons of Saul delivered to them to be punished, he delivered them up, but spared Mephibosheth the son of Jonathan. So when the Gibeonites had received the men, they punished them as they pleased; upon which God began to send rain, and to recover the earth to bring forth its fruits as usual, and to free it from the foregoing drought, so that the country of the Hebrews flourished again. A little afterward the king made war against the Philistines; and when he had joined battle with them, and put them to flight, he was left alone, as he was in pursuit of them; and when he was quite tired down, he was seen by one of the enemy, his name was Achmon, the son of Araph, he was one of the sons of the giants. He had a spear, the handle of which weighed three hundred shekels, and a breastplate of chain-work, and a sword. He turned back, and ran violently to slay [David] their enemy's king, for he was quite tired out with labor; but Abishai, Joab's brother, appeared on the sudden, and protected the king with his shield, as he lay down, and slew the enemy. Now the multitude were very uneasy at these dangers of the king, and that he was very near to be slain; and the rulers made him swear that he would no more go out with them to battle, lest he should come to some great misfortune by his courage and boldness, and thereby deprive the people of the benefits they now enjoyed by his means, and of those that they might hereafter enjoy by his living a long time among them.