Summary: Having left the Desert of Zif, David travelled to Ein Gedi to hide from Shaul but was discovered. Shaul entered a cave to relieve himself but unbeknownst to him, David and his men were hiding in the far end of the cave. They urged him to strike but David refused and instead cut off the corner of Shaul’s garment. David felt guilty for damaging the king’s garment. David stepped out of the cave and revealed himself to Shaul. Saul forgives David and they reconcile their differences.
A deeper look: David had had the opportunity to kill Shaul and was goaded by his men to carry out the act. Given that Shaul was a rodef (a pursuer threatening to murder and therefore subject to extra-judicial killing, see Sanhedrin 74a) David’s men saw a Divine opportunity to finish off their enemy. Yet Rabbi Levi ben Gershon (known as the Ralbag, d. 1344) explains that David resisted because Shaul was still the anointed king; killing him would have been a meridah b’malchus (treachery against the king). Furthermore such actions could set a dangerous precedent if David demonstrated that one could assassinate a Jewish king.
By tearing part of Shaul’s garment, he was able to show that he could have killed Shaul but chose not to. This inspired great remorse in the king and he wept, confessing that David was more righteous than him (Samuel I 24:17-18).
While their rapprochement came about through this one act, ripping the corner of Shaul’s garment carried great symbolism. David immediately felt guilty for doing so, for while he had spared Shaul’s life, damaging his clothing was also an act of treachery (Samuel I 24:6).
While David’s actions appear to be valiant, Rabbi Shabbatai Sheftil Weiss notes that God responded to David ‘what is the difference between cutting the tzitzit and cutting his head’? God would have saved David either way. Rabbi Shimon Ashkenazi HaDarshan of Frankfurt (c. 1260) explains that in addition, since David had cut the corner of Shaul’s garment, he prevented Shaul from performing the mitzvah of tzitzit (Yalkut Shimoni 133).
Rabbi Shmuel Laniado (16th century) also notes that since tzitzit remind a person of the 613 commandments, David prevented Shaul from benefitting from both the mitzvah and from the inspiration not to sin through murdering him; David had removed that extra protection from him (Kli Yakar).
Yet a new challenge was on the horizon with the death of one of the foremost Jewish leaders.