Charles H. Spurgeon on Psalms 40:10

I have not hid thy righteousness within my heart. On the contrary, "Never man spake like this man." God's divine plan of making men righteous was well known to him, and he plainly taught it. What was in our great Master's heart he poured forth in holy eloquence from his lips. The doctrine of righteousness by faith he spake with great simplicity of speech. Law and gospel equally found in him a clear expositor. I have declared thy faithfulness and thy salvation. Jehovah's fidelity to his promises and his grace in saving believers were declared by the Lord Jesus on many occasions, and are blessedly blended in the gospel which he came to preach. God, faithful to his own character, law and threatenings, and yet saving sinners, is a peculiar revelation of the gospel. God faithful to the saved ones evermore is the joy of the followers of Christ Jesus. I have not concealed thy lovingkindness and thy truth from the great congregation. The tender as well as the stern attributes of God, our Lord Jesus fully unveiled. Concealment was far from the Great Apostle of our profession. Cowardice he never exhibited, hesitancy never weakened his language. He who as a child of twelve years spake in the temple among the doctors, and afterward preached to five thousand at Gennesaret, and to the vast crowds at Jerusalem on that great day, the last day of the feast, was always ready to proclaim the name of the Lord, and could never be charged with unholy silence. He could be dumb when so the prophecy demanded and patience suggested, but otherwise, preaching was his meat and his drink, and he kept back nothing which would be profitable to his disciples. This in the day of his trouble, according to this Psalm, he used as a plea for divine aid. He had been faithful to his God, and now begs the Lord to be faithful to him. Let every dumb professor, tongue tied by sinful shame, bethink himself how little he will be able to plead after this fashion in the day of his distress.