John Calvin Commentary Hebrews 12:5

"and ye have forgotten the exhortation which reasoneth with you as with sons, My son, regard not lightly the chastening of the Lord, Nor faint when thou art reproved of him;" — Hebrews 12:5 (ASV)

And you have forgotten, etc. I read these words as a question, for the author asks whether they had forgotten, intimating that it was not yet time to forget. He then discusses the doctrine that it is useful and necessary for us to be disciplined by the cross. He refers to the testimony of Solomon, which includes two parts: first, that we are not to reject the Lord’s correction, and second, the reason given is that the Lord loves those whom he chastises. And as Solomon begins in this way, My son, the Apostle reminds us that we should be drawn by so sweet and kind a word, so that this exhortation may fully penetrate our hearts.

Now Solomon’s argument is this: if the scourges of God testify to his love for us, it is shameful that they should be regarded with dislike or hatred. For those who do not bear being chastised by God for their own salvation, indeed, who reject a proof of his paternal kindness, must be extremely ungrateful.