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

[319] Thus Saul having escaped the hands of David twice, he went his way to his royal palace, and his own city: but David was afraid, that if he staid there he should be caught by Saul; so he thought it better to go up into the land of the Philistines, and abide there. Accordingly, he came with the six hundred men that were with him to Achish, the king of Gath, which was one of their five cities. Now the king received both him and his men, and gave them a place to inhabit in. He had with him also his two wives, Ahinoam and Abigail, and he dwelt in Gath. But when Saul heard this, he took no further care about sending to him, or going after him, because he had been twice, in a manner, caught by him, while he was himself endeavoring to catch him. However, David had no mind to continue in the city of Gath, but desired the king, that since he had received him with such humanity, that he would grant him another favor, and bestow upon him some place of that country for his habitation, for he was ashamed, by living in the city, to be grievous and burdensome to him. So Achish gave him a certain village called Ziklag; which place David and his sons were fond of when he was king, and reckoned it to be their peculiar inheritance. But about those matters we shall give the reader further information elsewhere. Now the time that David dwelt in Ziklag, in the land of the Philistines, was four months and twenty days. And now he privately attacked those Geshurites and Amalekites that were neighbors to the Philistines, and laid waste their country, and took much prey of their beasts and camels, and then returned home; but David abstained from the men, as fearing they should discover him to king Achish; yet did he send part of the prey to him as a free gift. And when the king inquired whom they had attacked when they brought away the prey, he said, those that lay to the south of the Jews, and inhabited in the plain; whereby he persuaded Achish to approve of what he had done, for he hoped that David had fought against his own nation, and that now he should have him for his servant all his life long, and that he would stay in his country.