1 Samuel 1:22

“So I have also dedicated him to Yahweh; as long as he lives, he is dedicated to Yahweh.” So he worshiped Yahweh there.

And Samuel said to Saul, “You have acted foolishly; you have not kept the commandment of Yahweh your God, which He commanded you, for now Yahweh would have established your kingdom over Israel forever.

And David said to Achish, “Very well, you shall know what your servant can do.” So Achish said to David, “Very well, I will make you my bodyguard for life.”