2 Kings 6:21,22 - Joseph Benson’s Commentary on the Old and New Testaments

Shall I smite them? shall I smite them? This repetition of the question shows his eager desire to fall upon them and kill them. Perhaps he remembered how God was displeased at his father for dismissing out of his hands those whom he had put it into his power to destroy, and he would not offend in like manner: yet such reverence has he now for the prophet, that he will not lift a hand against them without his permission. He answered, Thou shall not smite them It is against the laws of humanity to kill captives, though thou thyself hadst taken them with thy own sword and bow, which might seem to give thee some colour to destroy them; but much more unworthy will it be in cold blood to kill these, whom not thy arms, but God's providence hath put into thy hands. Set bread before them Give them meat and drink, which may refresh and strengthen them for their journey. This was an action of singular piety and charity, in doing good to their enemies, which was much to the honour of the true religion, and of no less prudence; that hereby the hearts of the Syrians might be mollified toward the Israelites. Elijah had given a specimen of divine justice, when he called for flames of fire on the heads of his persecutors to consume them: but Elisha here gave a specimen of divine mercy, in heaping coals of fire on the heads of his persecutors to melt them.