In the dark recesses of the cave, a profound moral test unfolds. Urged by his loyal men to eliminate the man hunting him, David firmly refuses, offering a deeply principled defense for sparing King Saul's life.
The timing of David's response reveals the tension of the moment. After secretly cutting a corner of Saul's robe, David returns to his men. Seeing him return with only a piece of fabric rather than a decisive victory, his followers are bewildered as to why he did not seize the perfect opportunity to kill his pursuer [רד"ק]. In response to their unspoken wonder, David addresses their original suggestion to take Saul's life [רש"י].
David begins with a strong rejection, viewing the very idea of harming the king as a profane act that would directly violate God's commandment [מצודת דוד]. He makes it absolutely clear that he will not raise his hand to kill him [ביאור שטיינזלץ].
To explain his refusal, David refers to Saul using two distinct titles, representing two different levels of obligation. By calling Saul his master, David acknowledges his personal duty to his own king [ביאור שטיינזלץ] and the private respect owed to his father-in-law. By referring to him as God's anointed, David points to the broader national duty that all of Israel owes to their monarch. This distinction is crucial. If Saul were merely his father-in-law, David might be restricted from killing him but perhaps could still justify wounding him. However, because Saul is God's anointed, there is a total and absolute prohibition against causing him any harm whatsoever [חומת אנך].
David's men harbor the belief that the holy anointing has already departed from Saul, meaning his reign is effectively over and his time to die has arrived. To counter this, David repeats his assertion that Saul is still God's anointed. He assures his followers that he has carefully considered the situation and arrived at a clear conclusion: Saul remains the king whom God commanded to be anointed, and the oil upon his head has not lost its sacred status [מלבי"ם, ביאור שטיינזלץ].