Judah finishes his poignant and passionate plea delivered in Genesis 44: 18-34 by offering to stay in Egypt as a slave instead of Benjamin, who has just been accused of stealing by Joseph. One can only imagine what kind of emotions Joseph went through during Judas’s speech.
Here he was, a cunning and effective manager, who has devised an impenetrable plan aimed at reaching his ultimate goal of saving his younger beloved brother from the possible evil fate akin to one Joseph experienced himself. However, the main villain Judah suddenly turns into a chivalrous and humble man and utterly shutters the whole carefully orchestrated trap.
Thus Joseph cannot hold back his tears. Rashbam gives an amazingly modern commentary on this verse which sounds as if it was written yesterday, “YOSEF COULD NOT CONTROL HIMSELF. Any longer, for until now, he did all that he did by mental self-control”.
It seems like Rashbam himself knew very well about mental self-control. Joseph’s long and arduous journey to the heights of power required an immense amount of discipline and dedication to his goal. At this moment he is almost at the top and his plans are about to be fulfilled but everything crumbles when Judah is ready to perform the act of self-sacrifice. Therefore, Joseph cries out not only in great emotional turmoil but also in relief as he no longer needs to maintain the stiff upper lip.