Charles H. Spurgeon on Psalms 119:172

My tongue shall speak of thy word. When he had done singing he began preaching. God's tender mercies are such that they may be either said or sung. When the tongue speaks of God's word it has a most fruitful subject; such speaking will be as a tree of life, whose leaves shall be for the healing of the people. Men will gather together to listen to such talk, and they will treasure it up in their hearts. The worst of us is that for the most part we are full of our own words, and speak but little of God's word. Oh, that we could come to the same resolve as this godly man, and say henceforth, "My tongue shall speak of thy word." Then should we break through our sinful silence; we should no more be cowardly and half hearted, but should be true witnesses for Jesus. It is not only of God's works that we are to speak, but of his word. We may extol its truth, its wisdom, its preciousness, its grace, its power; and then we may tell of all it has revealed, all it has promised, all it has commanded, all it has effected. The subject gives us plenty of sea room; we may speak on for ever: the tale is for ever telling, yet untold.

For all thy commandments are righteousness. David appears to have been mainly enamoured of the preceptive part of the word of God, and concerning the precept his chief delight lay in its purity and excellence. When a man can speak this from his heart, his heart is indeed a temple of the Holy Ghost. He had said aforetime (Psalms 119:138), "Thy testimonies are righteous, "but here he declares that they are righteousness itself. The law of God is not only the standard of right, but it is the essence of righteousness. This the Psalmist affirms of each and every one of the precepts without exception. He felt like Paul "The law is holy, and the commandment holy and just and good." When a man has so high an opinion of God's commandments it is little wonder that his lips should be ready to extol the ever glorious One.