What does "va'Yisnakeir Aleihem" mean?
Rashi: He spoke to them harshly, like a stranger. 1
Ramban #1: He wore a turban which partially covered his face, so that they would not recognize him. 2
Ohr ha'Chayim: Even though he recognized them, i.e. conducted with brotherly love, towards them he concealed this. This was to get them to bring Binyamin, and to test how they feel about him. He found that they regretted the sale.
Gur Aryeh: We should not translate "va'Yisnakeir" as derived from 'Heker' - recognition, but rather from "Nochri" - stranger. It is in reflexive (Hispa'el) form - i.e. "he made himself into a stranger."
Like the wife of Yarav'am (See Melachim I 14:2 [Ramban]).
Why did Yosef speak to them harshly?
Seforno: Yosef in his humility, tended to speak softly. Consequently, afraid that that would recognize him by his voice, he changed his tone of voice to keep his identity hidden from them until he was ready to divulge it. 1
Ramban: He spoke to them in a tone of anger, as if nobody came to him to purchase grain. Yosef did so in order to hide his identity.
Malbim: It was to scare them, so they would not recognize him.
Riva, Moshav Zekenim (43:7): Yosef did not reveal himself immediately, lest amidst fear and shame, they say that he may not, due to the Shevu'ah they made him take when they sold him. Rather, he will force them to bring Binyamin and claim that he will be his slave, and they will be pressed to allow him to reveal himself (Riva; Moshav Zekenim - Yaakov will come and recognize Yosef.) It seems that they do not hold that the brothers told Yosef that they came with intent to bring back Yosef. Refer to 42:14:1:1. Yosef revealed himself before they consented! Perhaps it was clear that they consented, or he was forced, lest they kill all of Egypt. (PF)
Yosef asked only where they are from. Why did they add that they came to buy food?
Malbim: This indicates that they were coming to clear themselves of a sin (they had sold Yosef, and came to redeem him), and justified Yosef's accusation that they are spies.
Ha'amek Davar: It was clear from their clothes and language that they were from Kena'an. If so, "from where did you come" presumes that they did not come from their houses, rather, from elsewhere, and not in order to buy food. They answered, we came from our house to buy food.
Why is "Aleihem" written without a Yud in this entire Parshah?
Ha'amek Davar: He did not speak to them directly, rather, through an interpreter.
