John Calvin on Punishment to the 3rd and 4th Generations

 Calvin on visiting the iniquities of fathers to the children unto the 3rd and 4th generation: https://biblehub.com/commentaries/calvin/deuteronomy/5.htm

"To visit iniquities," is equivalent to inquiring into them, or taking cognizance of them, in order that punishment should be inflicted in proportion to the crime; for as long as God spares men and suspends His judgment, He seems to connive at them, or to pay no attention to them. Therefore, when men shall think that their sin is buried, He declares that He will bear it in memory. But it may be asked, how it is consistent for God to exact punishment from the children or grandchildren on account of the sins of their fathers? for nothing is more unreasonable than that the innocent and guilty should be involved in the same punishment; and the declaration of the Prophet is well known,

"The son shall not bear the iniquity of the father, neither shall the father bear the iniquity of the son; but the soul that sinneth, it shall die." (Ezekiel 18:20.)

The difficulty, which arises from the words of the Prophet, is easily solved, for God therein refutes the wicked expostulation of the people, that their children, who were not in fault, were unjustly and cruelly exposed to punishment. The proverb was generally rife, that "the fathers had eaten sour grapes, and the children's teeth were set on edge;" but God replies, that not one of those with whom He was angry and severe was free from crime; and, therefore, that their complaint was false, since each of them received the recompense of his own iniquity. And this is most true, that God's severity never assails the innocent; and however the world may murmur against His judgments, that He will always be clear in condemning this person or that [87]

But when God declares that He will cast back the iniquity of the fathers into the bosom of the children, He does not mean that He will take vengeance on poor wretches who have never deserved anything of the sort; but that He is at liberty to punish the crimes of the fathers upon their children and descendants, with the proviso that they too may be justly punished, as being the imitators of their fathers. If any should object, that this is nothing more than to repay every one according to his works, we must remember that, -- whenever God blinds the children of the ungodly, casts them into a state of reprobation, (conjicit in sesum reprobum), and smites them with a spirit of madness or folly, so that they give themselves up to foul desires, and hasten to their final destruction, -- in this way the iniquity of the fathers is visited on their children. But suppose other punishments are added, all are under condemnation (convicti,) so that they have no ground for murmuring against God; and even then also God still proceeds to execute the vengeance which He here denounces; for, when He would direct one work to various objects, He uses wonderful and secret expedients. When He commanded the people of Canaan to be destroyed, it is certain that those, who then were living, were worthy of this punishment; yet, inasmuch as God foretold [88] that their iniquities were not yet full, we infer that He then inflicted the punishment upon them which He had deferred for 400 years. On this ground, Christ declares that the Jews of His time were guilty of all the blood that had been shed from that of Abel to the blood of Zacharias, the son of Barachias, (Matthew 23:35.) But if it be not agreeable to our judgment that God should repay every one according to his deserts, and yet that He at the same time requires the sins of their fathers of the children, we should remember that His judgments are a great depth; and, therefore, if anything in His dealings is incomprehensible to us, we must bow to it with sobriety and reverence. But since this doctrine will recur elsewhere, I have thought fit only to touch upon it lightly here. One question remains, how we can reconcile the statement of Paul, that the fifth commandment is the first with promise, (Ephesians 6:2,) whereas a promise is annexed to this second. The solution of this is easy; for if you duly consider, this promise, which we have now explained, is not peculiarly annexed to any single commandment, but is common to the whole first Table of the Law, and these refer to the whole service of God; but when it is said, "honor thy father and thy mother, that thy days may be long," the keeping of that commandment is particularly and specially sanctioned."

Matthew Poole on that passage in Matthew 23:33 concerning Christ’s words says:

“You (saith our Lord) confess that you are lineally descended from those who killed the prophets: you have not only their blood communicated to you, but their spirit; your behaviours and carriages towards me and my disciples have witnessed, and will yet further testify, that you are the children of those who killed the prophets in a moral as well as a natural sense; you inherit the same spirit, and are full of the same malice and rancour. They killed them, and you bury them: seeing there is no reclaiming you, go you on, fill up the measure of your fathers’ sins. There is something more to be added to make the iniquity of this nation full. You are a company of serpents, vipers, that cannot escape the damnation of hell.”