John Calvin Commentary Genesis 41:35

"And let them gather all the food of these good years that come, and lay up grain under the hand of Pharaoh for food in the cities, and let them keep it." — Genesis 41:35 (ASV)

Under the hand of Pharaoh. Since prosperity so intoxicates people that most of them make no provision for the future, but consume the present abundance through lack of self-control, Joseph advises the king to ensure that the country's produce is stored up.

Furthermore, the common people would also cultivate habits of frugality once they understood that this large quantity of grain was not collected by the king in vain, but that a remedy was sought by this means for some unusual calamity. In short, because luxury generally prevails in prosperity and wastes God's blessings, the restraint of authority was necessary. This is why Joseph directed that granaries should be established under the king's power and that grain should be gathered into them.

He finally concludes that the dream was useful, although at first sight it might seem sad and ominous, because immediately after the affliction was revealed, the means of cure were also suggested.