Charles H. Spurgeon on Psalms 40:5

It is Christ's speech, of whom the Psalm is made, and that relating unto his Father's resolved purposes and contrivings from eternity, and those continued unto his sending Christ into the world to die for us, as Ps 40:6-7. It follows so, as although his thoughts and purposes were but one individual act at first, and never to be altered; yet they became many, through a perpetuated reiteration of them, wherein his constancy to himself is seen...My brethren, if God have been thinking thoughts of mercy from everlasting to those that are his, what a stock and treasury do these thoughts arise to, besides those that are in his nature and disposition! This is in his actual purposes and intentions, which he hath thought, and doth think over, again and again, every moment. Many, O Lord my God, are thy wonderful works which thou hast done, and thy thoughts which are toward us, saith Jesus Christ; for Psalm 40 is a Psalm of Christ, and quoted by the apostle, and applied unto Christ in Hebrews 10, How many are thy thoughts toward us! —he speaks it in the name of the human nature —that is, to me and mine. If I would declare and speak of them, they are more than can be numbered. And what is the reason? Because God hath studied mercies, mercies for his children, even from everlasting. And then, "He renews his mercies every morning; "not that any mercies are new, but he actually thinketh over mercies again and again, and so he brings out of his treasury, mercies both new and old, and old are always new. What a stock, my brethren, must this needs amount unto! Thomas Goodwin.