Verse 7. - I will be glad and rejoice in thy mercy. Anticipating the "mercy" which he has craved (vers. 2-4), the psalmist determines to "be glad and rejoice in it." For thou hast considered my trouble. When God looks upon trouble and considers it, he is sure to compassionate the sufferer, and to grant him some relief. Thou hast known my soul in adversities (comp. Psalm 1:6, "The Lord knoweth the way of the righteous" ). God is said to "know" those on whom he looks with approval.

31:1-8 Faith and prayer must go together, for the prayer of faith is the prevailing prayer. David gave up his soul in a special manner to God. And with the words, ver. 5, our Lord Jesus yielded up his last breath on the cross, and made his soul a free-will offering for sin, laying down his life as a ransom. But David is here as a man in distress and trouble. And his great care is about his soul, his spirit, his better part. Many think that while perplexed about their worldly affairs, and their cares multiply, they may be excused if they neglect their souls; but we are the more concerned to look to our souls, that, though the outward man perish, the inward man may suffer no damage. The redemption of the soul is so precious, that it must have ceased for ever, if Christ had not undertaken it. Having relied on God's mercy, he will be glad and rejoice in it. God looks upon our souls, when we are in trouble, to see whether they are humbled for sin, and made better by the affliction. Every believer will meet with such dangers and deliverances, until he is delivered from death, his last enemy.I will be glad, and rejoice in thy mercy,.... Both because of the nature of it, which is large and abundant, free and sovereign, from everlasting to everlasting, and is communicated in and through Christ, and is a good ground of hope and trust; and because of the effects of it, or what it has produced; for to it are owing the covenant of grace, and all the sure mercies of it; the mission of Christ, and redemption by him; regeneration, and the forgiveness of sins, and even eternal life and glory; besides a multitude of blessings, deliverances, and salvations in Providence; on account of all which there is great reason for joy and gladness; of which the following are particulars;

for thou hast considered my trouble; inward, arising from indwelling sin, doubts and fears, desertions and darkness, and Satan's temptations; and outward, from the world, and the men of it, and by reason of bodily afflictions: now the Lord looks upon the troubles of his people, and upon them in them, with an eye of pity and compassion; he sympathizes with them; he considers the nature of their trouble, their weakness to bear it, and the best way, in tans, and time to deliver out of it; he working all things after the counsel of his own will; see Exodus 3:7;

thou hast known my soul in adversities; that is, the Lord had took notice of him, approved of him, loved him, had visited him, and made known his love to him, and owned him for his own, and had chosen him in the furnace of affliction; a time and season when oftentimes friends and acquaintance are shy, and will not look upon men, know them, and own them; but the Lord does otherwise, and which is another reason of joy and gladness in his mercy.