John Calvin on Genesis 42:35

35. As they emptied their sacks. Here, again, it appears how greatly they had been alarmed in their journey, seeing that each had not at least examined his sack, after money had been found in one. But these things are written to show that, as soon as men are smitten with fear, they have no particle of wisdom and of soundness of mind, until God tranquilizes them. Moreover, Joseph did not act with sufficient consideration, in that he occasioned very great grief to his father, whose poverty he really intended to relieve. Whence we learn that even the most prudent are not always so careful, but that something may flow from their acts which they do not wish.