What is the Chidush that Yosef, a king, gave clothing to his brothers?
Hadar Zekenim: It was to honor them, for initially he called them spies.
Riva, citing R. Tam: It was compensation for causing them to tear their clothes when the cup was found in Binyamin's sack.
Why did Yosef give to Binyamin 300 silver pieces?
Riva #1, Hadar Zekenim: He hinted that half of the Beis ha'Mikdash, for which David paid 600 silver pieces for the place of it, will be in Binyamin's portion.
Riva #2, Rosh, Moshav Zekenim #1 citing R. Yehudah ha'Chasid: The other brothers sold Yosef to Chutz la'Aretz. One who does so is fined 10 times the price. We find that one pays 30 silver pieces if his ox gores an Eved Kena'ani. 1
Moshav Zekenim #2: Binyamin named his 10 sons after Yosef. Refer to 45:22:153:3.
Moshav Zekenim - he hinted to them that they are not getting this gift, due to the fine. Rosh - This was Chazal's source to fine 10 times his value! Riva - R. Elyakim rejected this. Reuven was not part of the sale! Refer to 37:29:1:1,2. (Also, the fine is 10 times what one received for the slave! Also, surely a slave as beautiful as Yosef was worth more than a normal slave! - PF)
Why did Yosef give to Binyamin five Chalifos (sets of clothing)?
Riva #1, Hadar Zekenim, from Megilah 16b: He hinted that Mordechai would descend from him, and be dressed in five royal garments. 1
Riva #2, Moshav Zekenim #1: They were for (a) causing him to tear his clothes, (b) because he was his full brother, (c) because he shamed him through a false accusation, (d) because he intended to obligate him Kefel (the extra payment of a thief), (e) and because he needlessly caused him to come to Mitzrayim.
Moshav Zekenim #2: Binyamin named his 10 sons after Yosef. Chalifos is two; he gave to him five Chalifos, i.e. 10. Together with the money, it is 310, the Gematriya of the initial letters of Binyamin and his sons.)
The Gemara asked how Yosef could stumble in favoring one son, which led to his sale. The Rosh and Moshav Zekenim (both on 37:3) ask, they would not be jealous, for Binyamin was his full brother! They answer that Yosef should have favored him through money, but not through clothing, which is openly seen. This is why the Gemara asked about the clothing, but not about the money that he gave only to Binyamin. Here, Moshav Zekenim says that the jealousy started when Yosef gave to him five times as much to eat, before the others knew that they are full brothers. The Gemara asked from this verse, in order to bring the hint to Mordechai. Peninim mi'Shulchan ha'Gra - the Gemara's question assumes that Binyamin's garments were worth more. Why should Yosef give to him five inferior garments that equal one of his brothers?! However, based on the answer that he hinted to Mordechai, we can say that indeed, Binyamin got inferior garments worth no more, to avoid jealousy! This is why "Chalifos" regarding Binyamin is written lacking a Vov.