1 Samuel 24:1-22

When Saul returned from following the Philistines, he was told, "David is
in the wilderness of En-gedi."  Then Saul took three thousand chosen men
out of all Israel, and went to look for David and his men in the direction
of the Rocks of the Wild Goats.  He came to the sheepfolds beside the
road, where there was a cave; and Saul went in to relieve himself.  Now
David and his men were sitting in the innermost parts of the cave.  The
men of David said to him, "Here is the day of which the LORD said to you,
'I will give your enemy into your hand, and you shall do to him as it
seems good to you.'"  Then David went and stealthily cut off a corner of
Saul's cloak.  Afterward David was stricken to the heart because he had
cut off a corner of Saul's cloak.  He said to his men, "The LORD forbid
that I should do this thing to my lord, the LORD's anointed, to raise my
hand against him; for he is the LORD's anointed."  So David scolded his
men severely and did not permit them to attack Saul.  Then Saul got up and
left the cave, and went on his way.

Afterwards David also rose up and went out of the cave and called after
Saul, "My lord the king!" When Saul looked behind him, David bowed with
his face to the ground, and did obeisance.  David said to Saul, "Why do
you listen to the words of those who say, 'David seeks to do you harm'?
This very day your eyes have seen how the LORD gave you into my hand in
the cave; and some urged me to kill you, but I spared you.  I said, 'I
will not raise my hand against my lord; for he is the LORD's anointed.'
See, my father, see the corner of your cloak in my hand; for by the fact
that I cut off the corner of your cloak, and did not kill you, you may
know for certain that there is no wrong or treason in my hands.  I have
not sinned against you, though you are hunting me to take my life.  May
the LORD judge between me and you!  May the LORD avenge me on you; but my
hand shall not be against you.  As the ancient proverb says, 'Out of the
wicked comes forth wickedness'; but my hand shall not be against you.
Against whom has the king of Israel come out?  Whom do you pursue?  A dead
dog?  A single flea?  May the LORD therefore be judge, and give sentence
between me and you.  May he see to it, and plead my cause, and vindicate
me against you."

When David had finished speaking these words to Saul, Saul said, "Is this
your voice, my son David?"  Saul lifted up his voice and wept.  He said to
David, "You are more righteous than I; for you have repaid me good,
whereas I have repaid you evil.  Today you have explained how you have
dealt well with me, in that you did not kill me when the LORD put me into
your hands.  For who has ever found an enemy, and sent the enemy safely
away?  So may the LORD reward you with good for what you have done to me
this day.  Now I know that you shall surely be king, and that the kingdom
of Israel shall be established in your hand.  Swear to me therefore by the
LORD that you will not cut off my descendants after me, and that you will
not wipe out my name from my father's house."  So David swore this to
Saul.  Then Saul went home; but David and his men went up to the
stronghold.