Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(v. 1-17) Joseph's policy to stay his brethren, and try their affection for Benjamin.
(v. 18-34) Judah's supplication to Joseph.
Joseph tried how his brethren felt towards Benjamin. Had they envied and hated the other son of Rachel as they had hated him, and if they had the same want of feeling towards their father Jacob as heretofore, they would now have shown it. When the cup was found upon Benjamin, they would have a pretext for leaving him to be a slave. But we cannot judge what men are now, by what they have been formerly; nor what they will do, by what they have done. The steward charged them with being ungrateful, rewarding evil for good; with folly, in taking away the cup of daily use, which would soon be missed, and diligent search made for it; for so it may be read, Is not this it in which my lord drinketh, as having a particular fondness for it, and for which he would search thoroughly? Or, By which, leaving it carelessly at your table, he would make trial whether you were honest men or not? They throw themselves upon Joseph's mercy, and acknowledge the righteousness of God, perhaps thinking of the injury they had formerly done to Joseph, for which they thought God was now reckoning with them. Even in afflictions wherein we believe ourselves wronged by men, we must own that God is righteous, and finds out our sin.
Had Joseph been, as Judah supposed him, an utter stranger to the family, he could not but be wrought upon by his powerful reasonings. But neither Jacob nor Benjamin need an intercessor with Joseph; for he himself loved them. Judah's faithful cleaving to Benjamin, now, in his distress, was recompensed long afterwards by the tribe of Benjamin keeping with the tribe of Judah, when the other tribes deserted it. The apostle, when discoursing of the mediation of Christ, observes, that our Lord sprang out of Judah, Heb 7:14; and he not only made intercession for the transgressors, but he became a Surety for them, testifying therein tender concern, both for his Father and for his brethren. Jesus, the great antitype of Joseph, humbles and proves his people, even after they have had some tastes of his loving-kindness. He brings their sins to their remembrance, that they may exercise and show repentance, and feel how much they owe to his mercy.