1 Samuel 27:8-28:4 New King James Version (NKJV)
8 And David and his men went up and raided the Geshurites, the [a]Girzites, and the Amalekites. For those nations were the inhabitants of the land from [b]of old, as you go to Shur, even as far as the land of Egypt. 9 Whenever David [c]attacked the land, he left neither man nor woman alive, but took away the sheep, the oxen, the donkeys, the camels, and the apparel, and returned and came to Achish. 10 Then Achish would say, “Where have you made a raid today?” And David would say, “Against the southern area of Judah, or against the southern area of the Jerahmeelites, or against the southern area of the Kenites.” 11 David would save neither man nor woman alive, to bring news to Gath, saying, “Lest they should inform on us, saying, ‘Thus David did.’ ” And thus was his behavior all the time he dwelt in the country of the Philistines. 12 So Achish believed David, saying, “He has made his people Israel utterly abhor him; therefore he will be my servant forever.”
Saul Consults a Medium
28 Now it happened in those days that the Philistines gathered their armies together for war, to fight with Israel. And Achish said to David, “You assuredly know that you will go out with me to battle, you and your men.”
2 So David said to Achish, “Surely you know what your servant can do.”
And Achish said to David, “Therefore I will make you one of my chief guardians forever.”
Saul Consults a Medium
3 Now Samuel had died, and all Israel had lamented for him and buried him in Ramah, in his own city. And Saul had put the mediums and the spiritists out of the land.
4 Then the Philistines gathered together, and came and encamped at Shunem. So Saul gathered all Israel together, and they encamped at Gilboa.