Yosef Has a Plan
Yosef's immediate reaction not to reveal himself to his brothers is quite understandable. But the sequence of events that follows is quite confusing. If Yosef simply wants to hide his identity from them, he can simply ignore them. Surely, Yosef did not entertain every foreigner who came to purchase food. So why does he accuse his brothers of being spies? Why does he return their money? Later, when they come back, why does he plant his special cup in Binyamin's bag?
Certainly, it appears to be more than random 'teasing' his brothers (to get back at them). Clearly, Yosef has a strategy, and his actions suggest that he has some sort of 'master plan,' but it is not so clear what that master plan is.
In his article, Rav Bin Nun explains Yosef's 'plan' as an attempt to determine what had happened to Binyamin. The fact that Binyamin was not with the brothers the first time they came to Egypt supports his suspicion that Bnei Rachel had been rejected. Therefore, his primary goal is to find out if Binyamin is still alive. If he is, then Yosef could question Binyamin concerning what 'really' happened in the family, and afterward Yosef could re-unite with his family. If he is not alive and/or if his father is already dead, then Yosef would most probably prefer never to reveal himself to his brothers. [This explains why Yosef accuses his brothers of being spies. The 'spy accusation' allows Yosef to question them concerning their family roots etc., without raising the suspicion that he may be their brother.]
Although this explanation flows nicely from the above presentation, it does not explain every detail of Yosef's behavior once Binyamin does arrive. After all, once Binyamin comes, why doesn't Yosef simply take him aside and question him. If Yosef only needs to determine what really happened in the "bechira" process, what point is there in planting his cup in Binyamin's bag? Surely, one cannot remain oblivious to Yosef's obvious attempt to create a situation that prompts the brothers to repent (as Avrabanel explains so beautifully).
On the other hand, one must also explain the reason for Yosef's returning their money, and for seating them in order of their birth, etc. These acts seem to be more of a 'tease' than an impetus for them to do "teshuva" (repentance). What is Yosef's intention in all of this? Furthermore, if his goal, as Avrabanel explains, is only to lead the brothers towards doing teshuva, then his 'second' plan seems unnecessary - after all, they had already shown remorse for their sin at the first encounter. Recall their initial remorse, that Yosef himself overheard them saying:
"Alas we are guilty, for we heard his crying out [when he was thrown in the pit], but we did not listen ... therefore this fate has befallen us..." (see 42:21-23!)Finally, if the Avrabanel's contention is correct, who gives Yosef the right to 'test' his brothers to see if they have repented? Is Yosef allowed to play God? Is it permitted to tease, trick, and confuse others in order to awaken their soul? Even so, does this justify causing his father further aggravation?