To "turn someone's heart" is to convince that person to change his affection. See how you translated a similar phrase in [1 Kings 11:01](./01.md). Alternate translation: "turned his heart away from Yahweh" or "persuaded him to stop worshiping Yahweh" (See: [[rc://en/ta/man/translate/figs-explicit]] and [[rc://en/ta/man/translate/figs-metonymy]])
To "surrender" your heart refers to giving total allegiance and affection. Alternate translation: "he was not fully devoted ... as was David" (See: [[rc://en/ta/man/translate/figs-metonymy]])