Why did Yusuf (peace be upon him) conceal his identity from his brothers when they first came, and why did he not reveal himself to them immediately, given the sorrow this caused his father and the hardship it caused his brothers?

Yusuf's (peace be upon him) actions toward his brothers were for a wisdom and benefit for himself, his father, his brothers, and their families. Some exegetes mentioned that this was by Allah's command, to increase Ya'qub's affliction and patience. It was also said that he did not reveal himself at first for fear that they might plot against him, so he resorted to those actions to draw attention and arrange his affairs. Ibn 'Ashur said that Yusuf did not reveal himself to them for fear that they might plot against him and his brother Benjamin, or because there were enmities between the Copts and the Canaanites, so he feared that if he brought his kin to Egypt, the King of Egypt might harbor ill suspicions. Therefore, he waited until he could arrange matters to bring his entire family honorably.