1 Samuel 27:3
And David dwelt with Achish at Gath, he and his men, every man with his household, even David with his two wives, Ahinoam the Jezreelitess, and Abigail the Carmelitess, Nabal’s wife. And David dwelt with Achish at Gath, he and his men, every man with his household, even David with his two wives, Ahinoam the Jezreelitess, and Abigail the Carmelitess, Nabal’s wife.
David settled with Achish at Gath, he and his men, every man with his household, bringing his own family and possessions and his two wives with him. His arrival had the appearance of a permanent relocation, as a Hebrew placing himself under the protection of the Philistine king. Achish welcomed these Israelite fugitives and gave promise to protect them.
He made the move to get beyond Saul's reach and to find asylum from Saul's attempts to kill him. He remained among the Philistines until Saul died. The decision reflected failing faith, because he did not seek God's counsel but relied on the Philistines for safety.
While there, his prudent and humble conduct made even his enemies peaceful toward him and willing to live at peace with him. Although he knew God had chosen him to rule Israel, he refused to kill Saul because God had anointed Saul. The Philistines welcomed him for their own advantage, hoping to separate his forces from Saul's army and to have him fight against Saul and Israel, which put David in a difficult position in which repaying their favor with deception was poor policy.