Charles H. Spurgeon on Psalms 119:29

Grant me thy law graciously. He opposes the law of God to the way of lying. First, because it is the only rule of all truth, both in religion and manners: that which is not agreeable to it is but a lie which shall deceive men. Secondly, it destroys and shall at length utterly destroy all contrary errors. As the rod of Aaron devoured the rods of the enchanters: so the word, which is the rod of the mouth of God, shall, in the end, eat up and consume all untruths whatsoever. Thirdly, according to the sentence of this word, so shall it be unto every man; it deceives none. Men shall find by experience it is true: he who walks in a way condemned by the word, shall come to a miserable end. And, on the contrary, it cannot but be well with them who live according to this rule. William Cowper.