Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Psa 36:1-4) The bad state of the wicked.
(Psa 36:5-12) The goodness of God.
From this psalm our hearts should be duly affected with hatred of sin, and seek satisfaction in God's loving-kindness. Here is the root of bitterness, from which all the wickedness of wicked men comes. It takes rise from contempt of God, and the want of due regard to him. Also from the deceit they put upon their own souls. Let us daily beg of God to preserve us from self-flattery. Sin is very hurtful to the sinner himself, and therefore ought to be hateful; but it is not so. It is no marvel, if those that deceive themselves, seek to deceive all mankind; to whom will they be true, who are false to their own souls? It is bad to do mischief, but worse to devise it, to do it with plot and management. If we willingly banish holy meditations in our solitary hours, Satan will soon occupy our minds with sinful imaginations. Hardened sinners stand to what they have done, as though they could justify it before God himself.
Men may shut up their compassion, yet, with God we shall find mercy. This is great comfort to all believers, plainly to be seen, and not to be taken away. God does all wisely and well; but what he does we know not now, it is time enough to know hereafter. God's loving-kindness is precious to the saints. They put themselves under his protection, and then are safe and easy. Gracious souls, though still desiring more of God, never desire more than God. The gifts of Providence so far satisfy them, that they are content with such things as they have. The benefit of holy ordinances is sweet to a sanctified soul, and strengthening to the spiritual and Divine life. But full satisfaction is reserved for the future state. Their joys shall be constant. God not only works in them a gracious desire for these pleasures, but by his Spirit fills their souls with joy and peace in believing. He quickens whom he will; and whoever will, may come, and take from him of the waters of life freely. May we know, and love, and uprightly serve the Lord; then no proud enemy, on earth or from hell, shall separate us from his love. Faith calleth things that are not, as though they were. It carries us forward to the end of time; it shows us the Lord, on his throne of judgment; the empire of sin fallen to rise no more.