1 Samuel 30:15

And David said to him, Canst thou bring me down to this company, to the place where the raiding troop had its permanent camp? And he said, Swear unto me by God that thou wilt neither kill me nor deliver me into the hands of my master, and I will bring thee down to this company. The caution of the Egyptian was due to the fact that informers and guides were often put to death by those whom they had served, while the hatred of those whom they had betrayed may well be understood.