O Jehovah our God The prophet here reminds them that God had heard their prayers because his grace and their piety harmonized. Consequently, encouraged by their exemplary success in prayer, their posterity ought to call upon God, not merely pronouncing his name with their lips, but keeping his covenant with all their heart. He farther reminds us that if God does not display his glory so bountifully, and so profusely in every age, the fault is with men themselves, whose posterity have either utterly forsaken, or greatly declined from the faith of the fathers. It is not to be wondered at that God should withdraw his hand, or at least not stretch it forth in any remarkable way, when he beholds piety waxing cold on the earth. O God, thou hast been propitious to them. [1] From these words it is quite obvious that what the Psalmist had formerly said concerning Moses, Aaron, and Samuel, refers to the whole people; for surely they did not officiate as priests merely for their own benefit, but for the common benefit of all the Israelites. Hence the transition is more natural which he makes from these three to the remaining body of the people. For I neither restrict the relative, to these three persons, nor do I interpret them exclusively of the same, but I rather think that the state of the whole Church is pointed out; namely, that while God, at the prayers of the priests, was propitious to the Jews, he, at the same time, sharply punished them for their sins. For on the one hand, the prophet magnifies the grace of God in that he had treated the people so kindly, and had so mercifully forgiven their iniquity; on the other hand, he specifies those awful examples of punishment by which he punished them for their ingratitude, that their descendants might learn to submit themselves dutifully to him. For it must not be forgotten, that by how much God deals graciously with us, by so much will he the less easily endure that we should treat his liberality with scorn. In the close of the psalm he repeats the same sentence which we had in the fifth verse, only substituting his holy mountain instead of his footstool; and as for the sake of brevity he had formerly said somewhat obscurely qdvs hv', kadosh hu, he is holy, he now says more plainly, Jehovah our God is holy His intention is to show that God is not to be worshipped by the Israelites at random, (as the religion of the heathen depended upon fancy alone,) but that his worship is founded upon the assurance of faith.

Footnotes

1 - Hammond translates, "O God, thou was propitiated for their sakes." He observes, that lhm, lahem, which Calvin renders to them, is not to be understood barely in the sense of the dative case, "thou wast propitiated to them," or "forgavest them;" but means for them, that is, for their sakes: God sparing the people, for or on account of the prayers of Moses, Aaron, and Samuel. God did not destroy them when these holy and devoted men pleaded with him in their behalf; he spared them, and drew back the hand of vengeance in answer to prayer. Such was the effect of Moses' intercessions. When the people caused Aaron to make the golden calf and worshipped it, God's anger was kindled against them. And he said to Moses, "Now therefore, let me alone, that my wrath may wax hot, and that I may consume them, and I will make of thee a great nation." Had Moses let God alone, the whole of that race would have been utterly consumed. But he pleaded with God in their behalf, and "the Lord repented him of the evil which he thought to do unto the people," Exodus 22:10-15. Nor was Aaron less prevalent in turning away the anger of God from the rebellious Israelites, as is evident from Numbers 16:43-45. When, on the occasion of the rebellion and murmuring of the people at Moses and Aaron on account of what befell Korah and his company, God said to Moses, "Get thee up from among this congregation, that I may consume them as in a moment;" Moses and Aaron "fell upon their faces," and prayed. Then it follows, verse 46, "And Moses said unto Aaron, Take a censer, and put fire therein from off the altar; and put on incense, and go quickly unto the congregation, and make an atonement for them; for there is wrath gone out from the Lord; the plague is begun. And Aaron took as Moses commanded, and ran into the midst of the congregation; and, behold, the plague was begun among the people: and he put on incense, and made an atonement for the people. And he stood between the dead and the living; and the plague was stayed." Equally successful were the intercessions of Samuel. When the Israelites were sore pressed by the Philistines, and afraid of them, they "said to Samuel, Cease not to cry unto the Lord our God for us, that he will save us out of the hand of the Philistines." Samuel did as they desired, and God was propitiated by his prayers: "Samuel took a sucking lamb, and offered it for a burnt-offering wholly unto the Lord; and Samuel cried unto the Lord for Israel, and the Lord answered him." -- 1 Samuel 7:7, 8, 9

Thou answeredst them, O Lord our God - The reference here is to God as "our" God; that is, the language used by those who now worship him is designed to give encouragement in approaching his throne. The God that "we" worship is the same that "they" worshipped; and as he answered them, we may feel assured that he will answer us.
Thou wast a God that forgavest them - They were not perfect; they were sinners; they often offended thee, and yet thou didst answer them, and show them mercy.
Though thou tookest vengeance - Though thou didst manifest thy displeasure at their misconduct; though thou in thy judgments didst show that thou wast displeased with them; nevertheless thou didst answer them. Sinners as they were, and often as thou didst show thy displeasure at their conduct, yet thou didst hear their prayers and bless them.
Of their inventions - The Hebrew word denotes work, deed, doing, conduct. It means here what they did - their sins. There is no allusion to any special art or "cunning" in what they did - as if they had "invented" or found out some new form of sin.

Thou - forgavest them - When the people had sinned, and wrath was about to descend on them, Moses and Aaron interceded for them, and they were not destroyed.
Tookest vengeance of their inventions - God spared them, but showed his displeasure at their misdoings. He chastised, but did not consume them. This is amply proved in the history of this people.

Thou answeredst them, O LORD our God: thou wast a God that forgavest them, though thou tookest vengeance of (e) their inventions.
(e) The more liberally God deals with his people, the more he punishes them who abuse his benefits.

Thou answeredst them, O Lord our God,.... This is repeated to show the certainty of it, and to encourage the people of God, in all ages, to pray unto him:
thou wast a God that forgavest them; even Moses, Aaron, and Samuel; for, though they were great and good men, they did not live without sin, and stood in need of pardoning grace and mercy, which they had; or rather the people for whom they prayed: so the Targum,
"O God, thou wast forgiving thy people for them;''
that is, through their prayers; see Numbers 14:19,
though thou tookest vengeance of their inventions; their sins, which are the inventions of men, Ecclesiastes 7:29. Kimchi and others interpret this of the inventions, designs, and practices of Korah, Dathan, and Abiram, against Moses and Aaron, Numbers 16:32 but though God took vengeance on them, it does not appear that he forgave their iniquities; wherefore it is best to understand this either of the sins of Moses and Aaron themselves, which, though pardoned, God took vengeance of, and showed his displeasure at, by not suffering them to go into the land of Canaan, Numbers 20:10, or else of the sins of the Israelites, who murmured upon the report of the spies; and though they were pardoned at the intercession of Moses, yet so far vengeance was taken upon them, that none of them were suffered to enter the land of Canaan; but their carcasses fell in the wilderness, Numbers 14:19, and thus, though God forgives the iniquities of his people, for the sake of his Son, yet he takes vengeance of them on him, their surety; on whom they have been laid and borne, and who has not been spared in the least; but has bore the whole wrath and vengeance of God due to sin; and besides, though he pardons his people, yet he chastises them for their sins, and shows his fatherly displeasure at them.

Them - The intercessors before mentioned. Forgavest - The people for whom they prayed, so far as not to inflict that total destruction upon them which they deserved;