May The Lord Be Between You And Me, 1 Samuel 19-20.

1 Samuel 20:2, 42 So Jonathan said to him, “By no means! You shall not die! Indeed, my father will do nothing either great or small without first telling me. And why should my father hide this thing from me? It is not so!” Then Jonathan said to David, “Go in peace, since we have both sworn in the name of the Lord, saying, ‘May the Lord be between you and me, and between your descendants and my descendants, forever.’” So he arose and departed, and Jonathan went into the city.