This is a prayer containing a heavy complaint against them, who, introduce human doctrines instead of the word of God, and who, afterwards, by various new traditions and forms of worship disturb the church, and fill all things with a white-wash show of religion, and with the outward daubing of pharisaism and hypocrisy, so that wicked men and hypocrites reign on every side, as the last verse complains. For when human doctrines have once invaded the church, they go on to rage far and wide, and spread in all directions like a cancer; there is no end to their corruption and destructive influence; they take possession of all things and wonderfully vex and torment consciences: so that the number of the true saints and of those that truly fear God is few and small indeed: of this the infinite variety of papistical hypocrisy affords a manifest example. But we are consoled and comforted under all these afflictions by the consideration that God always raises up in his church, sometimes in this place and sometimes in that, his salvation; that is, his word and gospel; which, while the prophets, apostles, and other ministers throughout the world, boldly and plainly teach against all heresy, they detect and bring to light false doctrines, and overturn all false worship; for where the salvation of God is, (that is, the saving word of Christ and his gospel) it burns up and consumes, like a suddenly-kindled fire, all the chaff and straw of human traditions, and delivers oppressed consciences. This, however, never takes place without afflictions, and the cross in various forms. But as gold and silver are proved by the fire, so the true knowledge and purity of the word is not preserved in the church but by means of the truly spiritual and godly, who for the word’s sake are exercised without and within by Satan, with various temptations: for these, like gold, are proved in the fire, and thus grow daily and flourish in the knowledge of the gospel, and the great things of God. This Psalm refers to the second and third precept of the Decalogue, and to the first and second petition of the Lord’s Prayer. PSALM XIII. _David complaineth of delay in help.—He prayeth for preventing grace.—He boasteth of divine mercy._ To the chief Musician. A Psalm of David. How long wilt thou forget me, O LORD? for ever? how long wilt thou hide thy face from me? How long shall I take counsel in my soul, _having_ sorrow in my heart daily? how long shall mine enemy be exalted over me? Consider _and_ hear me, O LORD my God; lighten mine eyes lest I sleep the _sleep_ of death; Lest mine enemy say, I have prevailed against him; _and_ those that trouble me rejoice when I am moved. But I have trusted in thy mercy; my heart shall rejoice in thy salvation. I will sing unto the LORD, because he hath dealt bountifully with me.