From Psalm 78...
Verse 36 Nevertheless they did flatter him with their mouth. Bad were they at their best. False on their knees, liars in their prayers. Mouth worship must be very detestable to God when dissociated from the heart: other kings love flattery, but the King of kings abhors it. Since the sharpest afflictions only extort from carnal men a feigned submission to God, there is proof positive that the heart is desperately set on mischief, and that sin is ingrained in our very nature. If you beat a tiger with many stripes you cannot turn him into a sheep. The devil cannot be whipped out of human nature, though another devil, namely, hypocrisy may be whipped into it. Piety produced by the damps of sorrow and the heats of terror is of mushroom growth; it is rapid in its springing up—"they enquired early after God"—but it is a mere unsubstantial fungus of unabiding excitement. And they lied unto him with their tongues. Their godly speech was cant, their praise mere wind, their prayer a fraud. Their skin deep repentance was a film too thin to conceal the deadly wound of sin. This teaches us to place small reliance upon professions of repentance made by dying men, or upon such even when the basis is evidently slavish fear, and nothing more. Any thief will whine out repentance if he thinks the judge will thereby be moved to let him go scot free.Verse 37. For their heart was not right with him. There was no depth in their repentance, it was not heart work. They were fickle as a weathercock, every wind turned them, their mind was not settled upon God. Neither were they stedfast in his covenant. Their promises were no sooner made than broken, as if only made in mockery. Good resolutions called at their hearts as men do at inns; they tarried awhile, and then took their leave. They were hot today for holiness, but cold towards it tomorrow. Variable as the hues of the dolphin, they changed from reverence to rebellion, from thankfulness to murmuring. One day they gave their gold to build a tabernacle for Jehovah, and the next they plucked off their earrings to make a golden calf. Surely the heart is a chameleon. Proteus had not so many changes. As in the ague we both burn and freeze, so do inconstant natures in their religion.
Verse 38. But he, being full of compassion, forgave their iniquity, and destroyed them not. Though they were full of flattery, he was full of mercy, and for this cause he had pity on them. Not because of their pitiful and hypocritical pretensions to penitence, but because of his own real compassion for them he overlooked their provocations. Yea, many a time turned he his anger away. When he had grown angry with them he withdrew his displeasure. Even unto seventy times seven did he forgive their offences. He was slow, very slow, to anger. The sword was uplifted and flashed in midair, but it was sheathed again, and the nation yet lived. Though not mentioned in the text, we know from the history that a mediator interposed, the man Moses stood in the gap; even so at this hour the Lord Jesus pleads for sinners, and averts the divine wrath. Many a barren tree is left standing because the dresser of the vineyard cries, "let it alone this year also." And did not stir up all his wrath. Had he done so they must have perished in a moment. When his wrath is kindled but a little men are burned up as chaff; but were he to let loose his indignation, the solid earth itself would melt, and hell would engulf every rebel. Who knoweth the power of thine anger, O Lord? We see the fulness of God's compassion, but we never see all his wrath.
Verse 39. For he remembered that they were but flesh. They were forgetful of God, but he was mindful of them. He knew that they were made of earthy, frail, corruptible material, and therefore he dealt leniently with them. Though in this he saw no excuse for their sin, yet he constrained it into a reason for mercy; the Lord is ever ready to discover some plea or other upon which he may have compassion. A wind that passeth away, and cometh not again. Man is but a breath, gone never to return. Spirit and wind are in this alike, so far as our humanity is concerned; they pass and cannot be recalled. What a nothing is our life. How gracious on the Lord's part to make man's insignificance an argument for staying his wrath.
Verse 40. How oft did they provoke him in the wilderness. Times enough did they rebel: they were as constant in provocation as he was in his patience. In our own case, who can count his errors? In what book could all our perverse rebellions be recorded? The wilderness was a place of manifest dependence, where the tribes were helpless without divine supplies, yet they wounded the hand which fed them while it was in the act of feeding them. Is there no likeness between us and them? Does it bring no tears into our eyes, while as in a glass, we see our own selves? And grieve him in the desert. Their provocations had an effect; God was not insensible to them, he is said to have been grieved. His holiness could not find pleasure in their sin, his justice in their unjust treatment, or his truth in their falsehood. What must it be to grieve the Lord of love! Yet we also have vexed the Holy Spirit, and he would long ago have withdrawn himself from us, were it not that he is God and not man. We are in the desert where we need our God, let us not make it a wilderness of sin by grieving him.
C.H. Spurgeon, from the Treasury of David