1 Samuel 30:13-15

13Then David said to him, “To whom do you belong, and where are you from?” And he said, “I am a young man from Egypt, servant of an Amalekite; and my master left me behind, because three days ago I fell sick.

14We made an invasion of the southern area of the Cherethites, in the territory which belongs to Judah, and of the southern area of Caleb; and we burned Ziklag with fire.”

15And David said to him, “Can you take me down to this troop?” So he said, “Swear to me by God that you will neither kill me nor deliver me into the hands of my master, and I will take you down to this troop.”