So Joseph imprisoned them for three days,
17. And he put them altogether into ward. Here, not by words only, as before, but by the act itself, Joseph shows himself severe towards his brethren, when he shuts them all up in prison, as if about to bring them to punishment: and during three days torments them with fear.
We may well wonder that Joseph, during the twenty years that he had now been in Egypt, especially during the last seven years that he had been in power there, never sent to his father to acquaint him with his circumstances; nay, it is strange that he who so often went throughout all the land of Egypt (Gen 41:45, Gen 41:46) never made an excursion...
Commenting on Genesis 42:7-20
And they said one to another,.... Before they went out of the prison, at least while in the presence of Joseph: we are verily guilty concerning our brother; meaning Joseph, whom they had sold for a slave, and who they supposed was dead through grief and hard servitude; and now being in trouble themselves, it brings to mind the sin they had been guilty of...