1 Samuel 19:6 in the King James Version
And Saul hearkened unto the voice of Jonathan: and Saul sware, As the LORD liveth, he shall not be slain.
Context
5 for he put his life in his hand and struck the Philistine, and the LORD worked a great victory for all Israel. You saw it and rejoiced. Why then will you sin against innocent blood, to kill David without a cause?”
6 Saul listened to the voice of Jonathan; and Saul swore, “As the LORD lives, he shall not be put to death.”
7 Jonathan called David, and Jonathan showed him all those things. Then Jonathan brought David to Saul, and he was in his presence as before.