The latter part of this psalm, which begins in the middle of a verse, is an exhortation to those who sing gospel psalms to live gospel lives, and to hear the voice of God’s word; otherwise, how can they expect that he should hear the voice of their prayers and praises? Observe,

I. The duty required of all those that are the people of Christ’s pasture and the sheep of his hand. He expects that they hear his voice, for he has said, My sheep hear my voice, Jn. 10:27. We are his people, say they. Are you so? Then hear his voice. If you call him Master, or Lord, then do the things which he says, and be his willing obedient people. Hear the voice of his doctrine, of his law, and, in both, of his Spirit; hear and heed; hear and yield. Hear his voice, and not the voice of a stranger. If you will hear his voice; some take it as a wish, O that you would hear his voice! that you would be so wise, and do so well for yourselves; like that, If thou hadst known (Lu. 19:42), that is, O that thou hadst known! Christ’s voice must be heard to-day; this the apostle lays much stress upon, applying it to the gospel day. While he is speaking to you see that you attend to him, for this day of your opportunities will not last always; improve it, therefore, while it is called to-day, Heb. 3:13, 15. Hearing the voice of Christ is the same with believing. To-day, if by faith you accept the gospel offer, well and good, but to-morrow it may be too late. In a matter of such vast importance nothing is more dangerous than delay.

II. The sin they are warned against, as inconsistent with the believing obedient ear required, and that is hardness of heart. If you will hear his voice, and profit by what you hear, then do not harden your hearts; for the seed sown on the rock never brought any fruit to perfection. The Jews therefore believed not the gospel of Christ because their hearts were hardened; they were not convinced of the evil of sin, and of their danger by reason of sin, and therefore they regarded not the offer of salvation; they would not bend to the yoke of Christ, nor yield to his demands; and, if the sinner’s heart be hardened, it is his own act and deed (he hardening it himself) and he alone shall bear the blame for ever.

III. The example they are warned by, which is that of the Israelites in the wilderness.

1. "Take heed of sinning as they did, lest you be shut out of the everlasting rest as they were out of Canaan." Be not, as your fathers, a stubborn and rebellious generation, Ps. 78:8. Thus here, Harden not your heart as you did (that is, your ancestors) in the provocation, or in Meribah, the place where they quarrelled with God and Moses (Ex. 17:2-7), and in the day of temptation in the wilderness, v. 8. So often did they provoke God by their distrusts and murmurings that the whole time of their continuance in the wilderness might be called a day of temptation, or Massah, the other name given to that place (Ex. 17:7), because they tempted the Lord, saying, Is the Lord among us or is he not? This was in the wilderness, where they could not help themselves, but lay at God’s mercy, and where God wonderfully helped them and gave them such sensible proofs of his power and tokens of his favour as never any people had before or since. Note, (1.) Days of temptation are days of provocation. Nothing is more offensive to God than disbelief of his promise and despair of the performance of it because of some difficulties that seem to lie in the way. (2.) The more experience we have had of the power and goodness of God the greater is our sin if we distrust him. What, to tempt him in the wilderness, where we live upon him! This is as ungrateful as it is absurd and unreasonable. (3.) Hardness of heart is at the bottom of all our distrusts of God and quarrels with him. That is a hard heart which receives not the impressions of divine discoveries and conforms not to the intentions of the divine will, which will not melt, which will not bend. (4.) The sins of others ought to be warnings to us not to tread in their steps. The murmurings of Israel were written for our admonition, 1 Co. 10:11.

2. Now here observe,

(1.) The charge drawn up, in God’s name, against the unbelieving Israelites, v. 9, 10. God here, many ages after, complains of their ill conduct towards him, with the expressions of high resentment. [1.] Their sin was unbelief: they tempted God and proved him; they questioned whether they might take his word, and insisted upon further security before they would go forward to Canaan, by sending spies; and, when those discouraged them, they protested against the sufficiency of the divine power and promise, and would make a captain and return into Egypt, Num. 14:3, 4. This is called rebellion, Deu. 1:26, 32. [2.] The aggravation of this sin was that they saw God’s work; they saw what he had done for them in bringing them out of Egypt, nay, what he was now doing for them every day, this day, in the bread he rained from heaven for them and the water out of the rock that followed them, than which they could not have more unquestionable evidences of God’s presence with them. With them even seeing was not believing, because they hardened their hearts, though they had seen what Pharaoh got by hardening his heart. [3.] The causes of their sin. See what God imputed it to: It is a people that do err in their hearts, and they have not known my ways. Men’s unbelief and distrust of God, their murmurings and quarrels with him, are the effect of their ignorance and mistake. First, Of their ignorance: They have not known my ways. They saw his work (v. 9) and he made known his acts to them (Ps. 103:7); and yet they did not know his ways, the ways of his providence, in which he walked towards them, or the ways of his commandments, in which he would have them to walk towards him: they did not know, they did not rightly understand and therefore did not approve of these. Note, The reason why people slight and forsake the ways of God is because they do not know them. Secondly, Of their mistake: They do err in their heart; they wander out of the way; in heart they turn back. Note, Sins are errors, practical errors, errors in heart; such there are, and as fatal as errors in the head. When the corrupt affections pervert the judgment, and so lead the soul out of the ways of duty and obedience, there is an error of the heart. [4.] God’s resentment of their sin: Forty years long was I grieved with this generation. Not, The sins of God’s professing people do not only anger him, but grieve him, especially their distrust of him; and God keeps an account how often (Num. 14:22) and how long they grieve him. See the patience of God towards provoking sinners; he was grieved with them forty years, and yet those years ended in a triumphant entrance into Canaan made by the next generation. If our sins have grieved God, surely they should grieve us, and nothing in sin should grieve us so much as that.

(2.) The sentence passed upon them for their sin (v. 11): "Unto whom I swore in my wrath, If they shall enter into my rest, then say I am changeable and untrue:" see the sentence at large, Num. 14:21, etc. Observe, [1.] Whence this sentence came—from the wrath of God. He swore solemnly in his wrath, his just and holy wrath; but let not men therefore swear profanely in their wrath, their sinful brutish wrath. God is not subject to such passions as we are; but he is said to be angry, very angry, at sin and sinners, to show the malignity of sin and the justice of God’s government. That is certainly an evil thing which deserves such a recompence of revenge as may be expected from a provoked Deity. [2.] What it was: That they should not enter into his rest, the rest which he had prepared and designed for them, a settlement for them and theirs, that none of those who were enrolled when they came out of Egypt should be found written in the roll of the living at their entering into Canaan, but Caleb and Joshua. [3.] How it was ratified: I swore it. It was not only a purpose, but a decree; the oath showed the immutability of his counsel; the Lord swore, and will not repent. It cut off the thought of any reserve of mercy. God’s threatenings are as sure as his promises.

Now this case of Israel may be applied to those of their posterity that lived in David’s time, when this psalm was penned; let them hear God’s voice, and not harden their hearts as their fathers did, lest, if they were stiffnecked like them, God should be provoked to forbid them the privileges of his temple at Jerusalem, of which he had said, This is my rest. But it must be applied to us Christians, because so the apostle applies it. There is a spiritual and eternal rest set before us, and promised to us, of which Canaan was a type; we are all (in profession, at least) bound for this rest; yet many that seem to be so come short and shall never enter into it. And what is it that puts a bar in their door? It is sin; it is unbelief, that sin against the remedy, against our appeal. Those that, like Israel, distrust God, and his power and goodness, and prefer the garlick and onions of Egypt before the milk and honey of Canaan, will justly be shut out from his rest: so shall their doom be; they themselves have decided it. Let us therefore fear, Heb. 4:1.