Matthew Henry Bible Commentary

Here is, 1. David's constancy in his religion. He had not departed from God's judgments; he had not chosen any other rule than the word of God, nor had he wilfully deviated from that rule. A constant adherence to the ways of God in trying times will be a good evidence of our integrity. 2. The cause of his constancy: "For thou hast taught me; that is, they were divine instructions that I learned; I was satisfied that the doctrine was of God, and therefore I stuck to it." Or rather, "It was divine grace in my heart that enabled me to receive those instructions." All the saints are taught of God, for he it is that gives the understanding; and those, and those only, that are taught of God, will continue to the end in the things that they have learned.