| Matthew Henry's Concise Commentary 78:9-39. Sin dispirits men, and takes away the heart. Forgetfulness of God's works is the cause of disobedience to his laws. This narrative relates a struggle between God's goodness and man's badness. The Lord hears all our murmurings and distrusts, and is much displeased. Those that will not believe the power of God's mercy, shall feel the fire of his indignation. Those cannot be said to trust in God's salvation as their happiness at last, who can not trust his providence in the way to it. To all that by faith and prayer, ask, seek, and knock, these doors of heaven shall at any time be opened; and our distrust of God is a great aggravation of our sins. He expressed his resentment of their provocation; not in denying what they sinfully lusted after, but in granting it to them. Lust is contented with nothing. Those that indulge their lust, will never be estranged from it. Those hearts are hard indeed, that will neither be melted by the mercies of the Lord, nor broken by his judgments. Those that sin still, must expect to be in trouble still. And the reason why we live with so little comfort, and to so little purpose, is, because we do not live by faith. Under these rebukes they professed repentance, but they were not sincere, for they were not constant. In Israel's history we have a picture of our own hearts and lives. God's patience, and warnings, and mercies, imbolden them to harden their hearts against his word. And the history of kingdoms is much the same. Judgments and mercies have been little attended to, until the measure of their sins has been full. And higher advantages have not kept churches from declining from the commandments of God. Even true believers recollect, that for many a year they abused the kindness of Providence. When they come to heaven, how will they admire the Lord's patience and mercy in bringing them to his kingdom!
Pulpit CommentaryVerse 34. - When he slew them, then they sought him (comp. Exodus 32:28, 35; Exodus 33:4, 10; Numbers 11:33; Numbers 16:48, 49, etc.). The repentance is not always noticed in the Mosaic narrative, being, as it was, short-lived, if not even feigned (ver. 36). But, no doubt, after each outpouring of the Divine vengeance, there was at least some show of repentance, as noted in Exodus 33:4. And they returned - i.e. turned back from their evil courses - and inquired early after God; rather, earnestly (Cheyne, Canon Cook).
Gill's Exposition of the Entire BibleWhen he slew them,.... Some of them, the spies particularly; or when he threatened to slay them, or was about to do it: then they sought him; that is, those who either survived the slain, or were threatened with destruction; these sought the Lord by prayer and supplication, that he would not destroy them; the Targum is, "they repented and sought him;'' see Numbers 14:37, and they returned; from their evil ways, and by repentance, at least in show and appearance: and inquired early after God; but not earnestly, and with their whole hearts and spirits; the Targum is, "they prayed before God;'' which is often done, by carnal professors, in trouble; see Isaiah 26:16, Hosea 5:15.
Psalm 78:34 Parallel Commentaries Psalm 78:34 NIV
Psalm 78:34 NLT
Psalm 78:34 ESV
Psalm 78:34 NASB
Psalm 78:34 KJV Bible Hub: Online Parallel Bible | 
