27 And he asked them of their welfare, and said, Is your father well, the old man of whom ye spake? Is he yet alive? 28 And they answered, Thy servant our father is in good health, he is yet alive. And they bowed down their heads, and made obeisance. 29 And he lifted up his eyes, and saw his brother Benjamin, his mother’s son, and said, Is this your younger brother, of whom ye spake unto me? And he said, God be gracious unto thee, my son. 30 And Joseph made haste; for his bowels did yearn upon his brother: and he sought where to weep; and he entered into his chamber, and wept there.
For a third time the brothers bow themselves to Joseph. God has made good on His promises and then some!
Joseph is able to inquire whether his father is still alive under the guise of general politeness. But then his pretended formalities are tested when he sees Benjamin before him. Up to this point Joseph has had multiple interactions with his brothers, but only the ones who betrayed him. This is now the first time that he is seeing someone from his old life with whom he had a positive relationship. He had already been reunited to the worst parts of his past, but now here is the best!
Is it any wonder then that he finally loses it? At least he is able to hold back the tears long enough to retreat to a private room. For all we know, Joseph might have always intended to eventually reveal who he was to his brothers, but I would imagine that at this point he has to do so. He is so close to being a brother to Benjamin again, but only if he reveals his true identity. He doesn’t take that step just yet, but I assume that he expected to do so soon.