John Calvin Commentary Genesis 48:17

"And when Joseph saw that his father laid his right hand upon the head of Ephraim, it displeased him: and he held up his father`s hand, to remove it from Ephraim`s head unto Manasseh`s head." — Genesis 48:17 (ASV)

And when Joseph saw. Because by crossing his arms, Jacob had so placed his hands as to put his left hand on the head of the firstborn, Joseph wished to correct this action, as if it were a mistake. He thought that the error arose from dim eyesight; but his father followed the Spirit of God as his secret guide, to transfer the title of honor, which nature had conferred on the elder, to the younger.

For, as he did not rashly assume the office of conveying the blessing, so it was not lawful for him to attempt anything according to his own will. And eventually, it became evident from the event that whatever he had done had been dictated to him by heaven.

Joseph was displeased that Manasseh, who by right of nature was first, was demoted to second place. This displeasure arose from faith and from holy reverence for the prophetic office. For he would easily have tolerated seeing his father make a mistake in the order of embracing the youths, if he had not known that his father, as a minister of divine grace, so far from performing a pointless act, was only pronouncing on earth what God would ratify in heaven.

Yet Joseph errs in binding the grace of God to the accustomed order of nature, as if the Lord did not often intentionally change the law of nature to teach us that what he freely confers on us is entirely the result of his own will. If God were giving to everyone their due, a certain rule might rightly be applied to the distribution of his favors; but since he owes no one anything, he is free to confer gifts at his own pleasure.

Especially, so that no one should glory in the flesh, he deliberately illustrates his own free mercy by choosing those who had no worthiness of their own. What shall we say was the cause why he raised Ephraim above his own brother, to whom, according to custom, he was inferior?

If anyone should suppose that Ephraim had some hidden seed of excellence, he not only engages in futile speculation but also impiously perverts the counsel of God. For since God derives from himself and from his own generosity the cause for preferring one of the two to the other, he confers the honor on the younger to show that he is bound by no claims of human merit, but that he distributes his gifts freely, as he sees fit.

And while this liberty of God extends to every kind of good, it nevertheless shines most clearly in the first adoption, by which he predestines to himself those whom he sees fit from the ruined mass. Therefore, let us leave to God his whole power untouched. If at any time our carnal sense rebels, let us recognize that none are more truly wise than those who are willing to consider themselves blind when contemplating the wonderful dealings of God, so that they may trace the cause of any difference he makes to himself alone.

We have seen above that Jacob's eyes were dim; but in crossing his arms, with apparent negligence, to comply with God’s purpose of election, he is more clear-sighted than his son Joseph, who, according to the sense of the flesh, inquires too keenly. Those who insanely imagine that this judgment was based on a view of their works sufficiently declare, by this one thing, that they do not hold the first principles of faith.

For the adoption common to both Manasseh and Ephraim was either a free gift or a reward for debt. Regarding this second supposition, all ambiguity is removed by many passages of Scripture, in which the Lord reveals his goodness in having freely loved and chosen his people. Now no one is so ignorant as not to perceive that the first place is not assigned to one or the other according to merit, but is given freely, since it so pleases the Lord.

Regarding the posture of the hands, the subtlety of certain persons who conjecture that the mystery of the cross was included in it is absurd. For the Lord intended nothing more than that the crossing of the right and left hands should indicate a change in the accustomed order of nature.