1 Samuel 23:12

And the Lord said, They will deliver thee up— One would imagine, that this extraordinary success, in the deliverance of so great a city, might have secured David a safe retreat among the men of Keilah; but it was not so: such is the nature of man; present dangers quickly obliterate past obligations. Gratitude is without question a most lovely virtue, but too seldom lives in the extremes either of adversity or success. It is like those fine colours which storms and sun-shine equally deface. This is an event which, methinks, will easily solve that hard question about the consistency of the divine prescience with human free-will. A good politician, who was let into the course of Saul's secret practices with the men of Keilah, and had fair opportunities of sifting their dispositions upon the point, might fairly pronounce upon the event: how much more then that all-seeing GOD, who searcheth the secrets of the heart, and seeth the thoughts afar off; seeth them in all their secret workings, tendencies, and temptations, and through all their mazes and masks. The treachery of the men of Keilah to David has given frequent occasion to observe how much more honourable was the conduct of the Athenians to their guardians, their orators, whom no threats could oblige them to give up to the resentment of Alexander.