Charles H. Spurgeon on Psalms 143:12

And of thy mercy cut off mine enemies, and destroy all them that afflict my soul. He believes that it will be so, and thus prophesies the event; for the words may be read as a declaration, and it is better so to understand them. We could not pray just so with our Christian light; but under Old Testament arrangements the spirit of it was congruous to the law. It is a petition which justice sanctions, but the spirit of love is not at home in presenting it. We, as Christians, turn the petition to spiritual use only. Yet David was of so generous a mind, and dealt so tenderly with Saul, that he could hardly have meant all that his words are made in our version to say. For I am lay servant; and therefore I hope that my Master will protect me in his service, and grant me victory while I fight his battles. It is a warrior's prayer, and smells of the dust and smoke of battle. It was heard, and therefore it was not asking amiss. Still there is a more excellent way.