In a rare moment of clarity, Saul openly admits his guilt and acknowledges David's superior moral standing. Looking back at their shared history, Saul confesses to his past wrongs and validates that David is entirely justified in his position [מלבי״ם].
When comparing how they have treated one another, Saul reflects on the nature of their mutual repayment. At its core, this concept refers to a basic reward or consequence for a specific action [מצודת ציון]. Yet, it also carries a profound emotional weight, describing acts of good or evil that stem directly from deep internal feelings of either love or animosity [מלבי״ם].
With this understanding, Saul admits that David always treated him with kindness born of true love and a sincere concern for his well-being. This loyalty was proven early on through David's battles against the Philistines and his defeat of Goliath. In sharp contrast, Saul confesses that his own treatment of David was a return of evil for good, fueled entirely by baseless hatred and hostility [מלבי״ם].