Why did Yosef weep over his brothers?
Rashi: Refer to 45:15:2:1.
Targum Yonasan: Because he foresaw that that they would be enslaved among the nations.
Why did the brothers not speak to Yosef earlier?
Rashi: Because until now they were embarrassed, and it was only after they saw the extent of his weeping and that he bore them no grudge that the barrier between them was removed.
Ohr ha'Chayim: Until now, they thought that perhaps Yosef bore them a grudge, and all his words were merely to spare them shame - and his crying they ascribed to his pain, or to his separation from Binyamin. But after he hugged them and cried over having been separated from them, they realized that he genuinely bore them brotherly love.
Ha'amek Davar: They were bewildered whe they saw his prophetic dream fulfilled. Initially they thought that perhaps he understands that they would be permanently subservient to him . But after he kissed them and cried over them like a brother, they understood that he considered the dream fulfilled and he was no longer a master over them.
