David had to leave town, because King Saul wanted to kill him. Saul knew God wanted David to be the next king. Saul didn't want to give up the kingdom. Saul and his army hunted for David and his men. David could have killed Saul on two occasions, but let him live. He knew God would decide the time of Saul's death. David and his men moved out of Israel, and pretended to be loyal to King Achish. They were secretly attacking Philistine cities, killing all possible witnesses.