On the third day Joseph said to them, “Do this and you will live, for I fear God:
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 Reuben answered them,.... Being the eldest, and who had been most concerned for the life of Joseph, and most tender and careful of him: saying, spake I not unto you, saying, do not sin against the child, and ye would not hear?
And Joseph said unto them the third day, This do, and live; [for] I fear God: (e) And therefore am true and just.