I'm not really sure if this would be considered an answer to my question, but inI’ve completely edited my opinion, it explains Rabbeinu Ephraim and subsequently, the Chida's thought process and helps clarify both the story of Miketz-Vayigash and the commentary itself. This is a summary of a class on this commentary given by Chabadnik Rabbi Mendel Kaplan and can be found here: https://www.chabad.org/multimedia/video_cdo/aid/2807492/jewish/Why-Benjamin-Was-in-Imminent-Threat.htm. Similarly, he gave another class on the topic in which I assume he gives over the same idea but haven't yet listened to: https://www.chabad.org/multimedia/video_cdo/aid/2814429/jewish/Benjamin-a-Preying-Wolf.htm
Everything in Vayigash worked out very well, although Yehudah couldn’t have known it would work out like that. What was going on? In Egypt there was a viceroy who was tormenting a band of Hebrews who’d come to Egypt to search for their brother, but they never found him and now this viceroy has put them in this impossible position where they have to bring their other brother, Binyamin, and now, instead of getting food and going back to Canaan, they’re faced with a situation where he’s being framed - supposedly he stole the goblet - and now the brothers are told that they can all go home, and Binyamin is to stay behind as a slave.
Now, from the beginning, when the brothers first went to Egypt, Binyamin wasn't sent to them, for fear that "פן יקראנו אסון", for fear that danger will come upon him. Rashi is bothered by this: "ובבית לא יקראנו אסון? - don't accidents happen at home as well? Don't people fall off the stairs of their homes?" Answers Rashi based on the midrash (Tanchuma Vayigash 1): "אמר רבי אלעזר בן יעקב, מכאן שהשטן מקטרג בשעת הסכנה" - the Satanic forces, the negative forces in the world can create difficult circumstances when we're in difficult situations. As they say in English, "don't tempt fate".
But this is a very odd and vague explanation. After all, Yaakov wasn't afraid to send his other sons on the road - twice, even. The commentaries (such as Ralbag and the Abarbanel, brought by Shadal) say that it was almost as if there was a chazakah that Rachel and her descendants were in danger of dying on the road: Rachel died on the road, Yosef disappeared (presumed dead by Yaakov) on the road, and Binyamin is the only descendant of Rachel left, and there's a fear the he too could die - but it's unclear what exactly is this danger [also considering that both Rachel and Yosef died for different reasons]answer.
What is really the problem, or what may have been the issue that Yaakov was so uncomfortable in sending Binyamin specifically out?
To understand this, we must first go to Yayigash and examine Yehudah's words to Yosef:
Then Judah went up to him and said, “Please, my lord, let your servant appeal to my lord, and do not be impatient with your servant, you who are the equal of Pharaoh. My lord asked his servants, ‘Have you a father or another brother?’ We told my lord, ‘We have an old father, and there is a child of his old age, the youngest; his full brother is dead, so that he alone is left of his mother, and his father dotes on him.’ Then you said to your servants, ‘Bring him down to me, that I may set eyes on him.’ We said to my lord, ‘The boy cannot leave his father; if he were to leave him, his father would die.’ But you said to your servants, ‘Unless your youngest brother comes down with you, do not let me see your faces.’ When we came back to your servant my father, we reported my lord’s words to him. “Later our father said, ‘Go back and procure some food for us.’ We answered, ‘We cannot go down; only if our youngest brother is with us can we go down, for we may not show our faces to the man unless our youngest brother is with us.’ Your servant my father said to us, ‘As you know, my wife bore me two sons. But one is gone from me, and I said: Alas, he was torn by a beast! And I have not seen him since. If you take this one from me, too, and he meets with disaster, you will send my white head down to Sheol in sorrow.’ “Now, if I come to your servant my father and the boy is not with us—since his own life is so bound up with his— when he sees that the boy is not with us, he will die, and your servants will send the white head of your servant our father down to Sheol in grief. Now your servant has pledged himself for the boy to my father, saying, ‘If I do not bring him back to you, I shall stand guilty before my father forever.’ Therefore, please let your servant remain as a slave to my lord instead of the boy, and let the boy go back with his brothers. For how can I go back to my father unless the boy is with me? Let me not be witness to the woe that would overtake my father!” (Genesis 44:18-34)
Let's examine this: Binyamin was allowed to go to Egypt only when Yaakov saw that there was no food and only when Yehudah too full responsibility to see to the safe return of Binyamin. Yehudah sees that now things are going south, so he proceeds to make a strong case to Yosef for the return of Binyamin: "You listen to me, and forgive me if I'm going to be harsh, but Binyamin is coming back with us! And I'll explain why: You asked, 'do we have a father and a brother?' You came to us in such a way as though there was some insidious plot going on, and that doesn’t make any sense! WhyHere are you asking personal questions? We just came to get provisions! Even if its an issue of national defense, what do personal questions [about our father and brother] have to do with anything? And we told you, we have an old father," - Ibn Ezra explains that Yehudah emphasized the word 'old' because at the time Reuven was a mere 45 years old - for any other person, their father would've been 65-70, which wasn't so old for the time. But Yaakov was indeed, really old at the time, and as such it's part of Yehudah's case: He's old, he has a weak heart, he's suffered a lot, etc. - "וילד זקונים" - the Malbim explains: He's small and tender. Which is odd: He was about 30 years old at the time - how long can you baby a child? - "the thing is, however, that "ואחיו מת, ויותר הוא לבדו לאמו ואביו אהבו" - he’s the only remembrance of his mother to his father." - Yaakov deeply loved Rachel, that’s why he has a special affection for Binyamin. - "ואביו אהבו – his father loves him so much, that you’d think he’s his only son, and that’s why he wasn’t willing to send him off. But you wanted to see him, and for all our trouble, we brought him, but this is what we get for doing what you said? That you try to take him away? "ועזב את אביו, ומת" - if he leaves his father, he'll die!"
This a very strange argument by Yehudah: Really, Binyamin will die if he leaves his father? Why? ? There’s a midrash that says (I couldn't find the midrash, but i found Radak saying something similar) that he was called “ben-yamin” – because he was always at Yaakov’s right side, and he leaned on him. But this is a little excessive! Talk about intensive separation anxiety! This doesn’t sound reasonable! If I were Yehudah, and I was trying to make a cogent argument, I wouldn’t say: if he leaves him, he’ll die, because guess what? He left him, and he didn’t die! Why would Yehudah say something like that?
But Yehudah continues: "And it came to pass when we came up unto thy servant my father, we told him the words of my lord. And our father said: Go again, buy us a little food. And thy servant my father said unto us:...and if ye take this one also from me, and harm befall him - "וקרהו אסון" - really matter-of-fact! Why is it certain that such an accident will happen? Doesn’t say. And once again, Rashi says on this verse that "שהשטן מקטרג בשעת הסכנה" - It doesn’t say what’s the sakkanah, it doesn’t say why it’s dangerous only for Binyamin and not the brothers! And yehudah uses very strong terms: “ועזב את אביו ומת” – what does that mean? How can he be so certain of this?
So there's a commentary of Rabbeinu Ephraim on Beresheet 2:28:
Tzelem is ze’ev in the albam system (אלב"ם); therefore, those people who change into wolves were created as such from the Six Days of Creation, and do not return to their earlier state until they have eaten the blood of a man or woman.
options I [the Rabbi] did a little research about werewolves: every single ancient civilization from the Far East to the New World, has a story about people turning into wolves. If you want to talk about people changing skins, why did everyone end up with the wolf? – these civilizations didn’t have contact with each other! The vast majority of transformation stories have to do with wolves. Similarly, everyone has a 7-day week, though this number doesn’t fit in with neither the solar calendar nor the lunar one.
So Rabbeinu Ephraim says that there used to be people who could change into wolves. Similarly, something that’s found in many civilizations is the story of the phoenix – a bird the burns up and is reborn. Well, guess what? It’s a midrash [the Oph Ha’Chol bird in Midrash Rabbah 19]. Well, some people would say: Ha, the midrash just appropriated Greek and Roman mythology, doesn’t mean it’s real! But that’s not how to Torah works. Jews don’t live for a bunch of collected myths from other religions with a sprinkling of Hebrew on them. Just because today we don’t see something, doesn’t mean that centuries ago, or millennia, it wasn’t so. If every civilization has the same kind of story, it is a tantalizing hint that in the past, it may very well have been so.
It is my belief that Rabbeinu Ephraim says this based on a midrash that was lost, and Rabbeinu Ephraim saw this as a reality: In the past, there were some people who could change into wolves. This explains Yaakov's seemingly irrational fear of letting Binyamin go - and the only reason he agreed was because the entire family was in danger of dying of starvation, coupled with Yehudah's solemn promise to bring Binyamin back. Yaakov was able to influence Binyamin into transforming back into human form - without the need for blood. But if he left Yaakov's side, he might transform into a wolf and no one would be able to handle him, he'll run off and be killed on the road - when people see a dangerous animal, they're prone to try to kill it:
For thus it says, “And he shall leave his father and die” (Gen. 44:22)—namely, that when he separates from his father, and turns into a wolf with travelers, whoever finds him will kill him.
Now, I assume Yosef was not aware that Binyamin was a wolf - otherwise he wouldn't have forced him to leave Yaakov's side and put him in real harm's way.
That's the gist of the class. Having further thought about @user6591's comments, I suppose they're correct about Binyamin being a baby when he supposedly (according to Rabbeinu Ephraim and this possible lost midrash) attacked Rachel - but this doesn't nullify the fact that these wolf-creatures appear to have been considered monsters of sorts (certainly they were considered wild, dangerous animals). However, it seems that these people were only "bad" in wolf-form, and the rest of the time they were regular people.
According to a comment on Rabbi Slifkin's post, over 20 years ago this question was sent to Rabbi Chaim Kanievsky and he wrote back:
- As Rabbi Chaim Kanievsky said (according to one of the comments on Rabbi Slifkin's post, he was sent this commentary over 20 years ago):
זה מסודי התורה - This is from the secrets (Sod) of the Torah.
I think it's important to further note, that this was discussed by Rabbi Yosef Aryeh Lorentz in his book Niflaot Edotaycha:
And I saw in Rabbeinu Ephraim's commentary on the Torah...that there's a kind of wolf who's a human and changes to a wolf...and so was brought by the Chida...and we need to examine whether such a being is considered human or wolf, or do we say that its species changes with its form...and this is an issue with Kidushei Isha if such a person then went and changed into a wolf - is his wife muteret [allowed to marry someone else] and it is as though the husband died and he went back and became human, does he once again retain his rights over her...and this is a very astonishing thing, that a man shall change into an animal and an animal into a man, for man has a soul and free will and reward and punishment, and when the man becomes a wolf - his soul, where is it, and when the wolf becomes a man, from did he get his soul, and because of this it seems that this kind of man that becomes a wolf doesn't have a soul of a man and only has the form of a man, and we call him 'man' based on his form and appearance...and if so, the laws of man don't apply to him..."
It seems, though, that Rabbi Lorentz didn't see Rabbeinu Ephraim's later Beresheet commentary on Binyamin being such a wolf, otherwise I doubt he would've said that such a creature doesn't have a soul.
One last note: Don't take me wrong, I don't necessarily agree with Rabbeinu Ephraim's pshat-take (or sod-take, according to Rabbi Kanievsky) on this, but the questions that are probably the basis for this idea - as shown in the class - are quite strong, and, after all, Rabbeinu Ephraim is a noted Rishon and the Chida is a noted (fairly-rishon) Acharon, and considering that many fantastic creatures appear all over the Tanach and Chazal, I think it's important to take this possibility seriously and not just say that it's based on the influence of Dark-Ages-Europe.
- Based on Rabbi Mendel Kaplan’s class (which can be found here: https://www.chabad.org/multimedia/video_cdo/aid/2807492/jewish/Why-Benjamin-Was-in-Imminent-Threat.htm), it appears to be based on a lost midrash. The basis for this assumption comes from Yaakov’s seemingly irrational and way over-the-top and completely-certain fear that his son Binyamin will be in grave danger if he leaves his side ("וקרהו אסון") – yet doesn’t hold the same fears with regards to his other sons, and these seemingly odd fears are further asserted in Yehudah's speech to Yosef in the beginning of Miketz. The answer, according to this lost midrash brought by Rabbeinu Ephraim is that Binyamin was in constant danger of changing back into wolf form, with the only person that was able to cure him without the need to spill blood being his father. If he were to leave his father's side and transform, he'd run off and be killed by the first person who meets him, as all wild and dangerous animals are killed.