Why didn't Yosef's brothers recognize him?

Question

The Posuk says (Genesis 42:8):

וַיַּכֵּר יוֹסֵף אֶת אֶחָיו וְהֵם לֹא הִכִּרֻהוּ

Translated as:

Now Joseph recognized his brothers, but they did not recognize him

The question is: How did they miss all the signs that were there:

1. In Posuk 42:18 he says "אֶת הָאֱ־לֹהִים אֲנִי יָרֵא", "I fear GOD".
2. And if you take the Gemara in Chulin 91a on a pshat level, he Shechted (ritually slaughtered) the animal and removed the Gid Hanashe (did Nikur). After seeing this, how did they not recognize him as Yosef their brother?

Answer 1

1. It had been decades (22 years, IIRC) since they had last seen him. When they had last seen him, he had been a teenager, and now he was an adult. Peoples' appearances and mannerisms change over time.
2. Yosef, in his position of power, dressed and acted like an Egyptian, and not like a Hebrew. (As noted by the mefarshim, different clothes, hairstyles, grooming methods, etc, all combined to completely change his appearance. See Rashbam and Chizkuni on that verse.)
3. Since they had sold him as a slave, it would have been inconcievable to them that the man before them, viceroy and second to the king, was their brother.
4. Yosef intentionally used an interpreter instead of talking in Hebrew to them, and actively tried to hide his identity. (See verses 7 and 23.)
5. Yosef treated them harshly. Would they have expected their brother to treat his family so?
6. Note that when he finally does reveal himself, they're shocked into silence. Implies that he was unrecognizable.

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In response to your arguments:

Genesis 42:18

1. האלוהים could have referred to an Egyptian god. (Unlikely, but possible.)
2. Even referring to the Jewish god, the brothers most likely understood his statement as one of tolerance and respect for their god, not that the viceroy was a monotheist and actively worshipped only their god. In which case, it would not have been odd, and maybe even expected, for them to hear such a statement.
3. האלוהים is a general term for a higher authority, and the statement merely means that he's honest and ethical. (Note that "אלוהים" is used in Chumash to refer to Beit Din.)

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Gemara Chullin

1. Is not included in the actual text of the story, and as such, cannot be used to raised questions on that which is present in the actual text.
2. Yosef slaughtered and prepared the food according to their customs in order to be respectful and hospitable. Like any good host, he made sure the food was to his guests' satisfaction. (Thanks to @avi)

Thus, it is impossible to conclude from his actions that he was one of them.

Answer 2

The brothers did not recognize him because Hashem withheld that ability from them. Hakol bechazkas sumin ad she'hskadosh Baruch Hu Meir es einayhem. A person is blind unless Hashem opens his eyes to see what has been hidden. I believe Rav Bloch gives this answer.

Answer 3

The Gemara itself asks this question (Kesuvos 25b) and answers that Yosef didn't have a beard when he left them, but had grown a full beard in the time since.

Regarding those Gemaras, R. Hirsch notes that despite being only one (albeit very large) family, the God and customs of the children of Yaakov were well known to the Egyptians, due to the tremendous fame and stature of the Avraham-Yitzchak-Yaakov trio. Thus, both Pharaoh and the mysterious Egyptian viceroy knew all about אלקים and the eating restrictions of the family of Yaakov (and they weren't happy with them either - לֹא יוּכְלוּן הַמִּצְרִים לֶאֱכֹל אֶת הָעִבְרִים לֶחֶם כִּי תוֹעֵבָה הִוא לְמִצְרָיִם, Beraishis 43:32)

Answer 4

Yonatan ben Uziel says in gen 42:8 that he recognized them because they had beards at the time they sold him, but they did not recognize him because he did not have a beard at the time of the sale, but he had one now.

Answer 5

i think that of course it dawned on them that it could be yosef but it was so beyond the realm of possibility that he could be king . like Rashi says they searched for him in the houses of ill repute because thats where they held he should be. true story- after 9-11 i was in israel by a melave malka and a bearded rabbi sat acreoss from me who looked EXACTLY like Bin Laden. now he was on the loose , so maybe it was him ? to which any sane person knows its IMPOSSIBLE that obl is sitting by a melave malka table in israel. so Yosefs brothers also felt , yes , it looks like him , he acts like him , but its just not him. you see its hard to change a preconceived notion and belief. and that was the shock of the revelation of yosef .

Answer 6

of course it dawned on them that it can be yosef. but to acknowledge that this was yosef would be an indictment on their actions and beliefs of the past 13 years . this they could not accept so they subconsciously dismissed the possibility that it could be him