John Calvin Commentary Genesis 44:2

"And put my cup, the silver cup, in the sack`s mouth of the youngest, and his grain money. And he did according to the word that Joseph had spoken." — Genesis 44:2 (ASV)

And put my cup, the silver cup. It may seem surprising that, considering his great opulence, Joseph did not instead drink out of a golden cup. Doubtless, either the moderation of that age was still greater than has since prevailed, and its splendor less sumptuous; or else this conduct must be attributed to the moderation of the man, who, in the midst of widespread lack of restraint, was nevertheless content with a plain and decent, rather than a magnificent, style of living.

Unless, perhaps, because of the excellence of the workmanship, the silver was more valuable than gold: as is clear from secular history, that the workmanship has often been more expensive than the material itself. It is, however, probable that Joseph was restrained in his household display to avoid envy.

For if he had not been prudently on his guard, a conflict would have arisen between him and the courtiers, stemming from a spirit of rivalry.

Moreover, he commands the cup to be placed in Benjamin’s sack, so that he might claim him as his own when convicted of the theft and might send the others away. However, he accuses them all equally, as if he did not know which of them had committed the crime.

First, he rebukes them for their ingratitude because, having been so kindly received, they made the worst possible return. Next, he argues that the crime was inexpiable, because they had stolen what was most valuable to him: namely, the cup in which he was accustomed both to drink and to divine. He does this through his steward, whom he had not trained to acts of tyranny and violence. From this, I infer that the steward was not entirely unaware of his master’s plan.