John Calvin's Bible Commentary
Jeremiah 33:22
There is an omission at the beginning; the particle of comparison is left out, for אשר asher, cannot be taken for כאשר caasher: As the hosts of the heavens cannot be numbered, nor the sand of the sea, so God promises that he would multiply the seed of David, and also the Levites. This promise, as given to Abraham, referred to the whole body of the people; for when Abraham was bidden to go out, and to look on the heavens, God made this promise to him, “Number the stars, if thou canst, and the sands of the sea, so shall thy seed be.” We hence see that this blessing was extended to the whole seed of Abraham, and especially to the twelve tribes. And now it is confined to the family of David, and to the Levitical tribe.
But what we have already touched upon ought to be borne in mind, — that the safety of the people was grounded on the kingdom and the priesthood. As then kings ruled not for themselves, nor had the sacerdotal dignity been given to the Levites for their own private advantage, but for the sake of the people, so now the Prophet, stating a part for the whole, intimates that the whole people would be secure and safe, when the royal and sacerdotal dignity flourished. There is not, then, anything diminished from God’s promise, as though the other tribes were not to multiply; but what Jeremiah testifies respecting the family of David and the Levitical tribe, is to be extended, without any difference, to the whole Church. It is yet not without reason that an especial mention is made of David and Levi; for, as it has been said, the Church must have been in a miserable state, without a head, and without a Mediator. There is, however, no doubt but that Jeremiah alluded to that passage which we have already quoted, (Genesis 15:5; Romans 4:18) and thus he reproved the want of faith in the people; for they could not have doubted the restoration of the Church without impugning the truth of God, as though he had given only vain words to Abraham, when he said,
“Number the stars of heaven if thou canst, and the sands of the sea, so shall thy seed be.”
He therefore shews that God would be true and faithful in that promise, so as to multiply his Church like the stars of heaven, and the sands of the sea. It follows —