vayigash

ויאמר יוסף אל אחיו- אני יוסף-ולא יכלו אחיו לענות אותו כי נבהלו מפניו
The Medrash says on this Posuk, woe is the Day of Judgment; woe is the day of rebuke. Just as the brothers weren't able to answer Yosef who was the youngest of the Shevatim, how much more so will we be unable to answer Hashem when He will rebuke us.
Rav Isaac Sher asks where do you see that Yosef gave them any Tochacha? All it says is that he raised his voice and cried. Not only didn't he give them Tochacha, he had everyone else leave the room so his brothers wouldn't be embarrassed. Where do you see the rebuke that the Medrash says they couldn't answer him?
The Posuk says later on that Yosef sent his father 10 donkeys laden with all the good of Mitzrayim. Rashi says the best of Mitzrayim is referring to aged wine.
Egypt isn't known for its wine, so what was Yosef trying to tell Yaakov by sending him aged wine?
The Mayana Shel Torah says he was trying to relieve his father’s worries, that just like the wine in the jug is old & unchanged, so too Yosef even though his outside looks different since he's now the viceroy of Egypt. He still retained his upbringing and is unchanged on the inside.
R' Shloima Alter says that wine ages & gets better as it gets older, but that's only if the wine starts out good. If you use bad wine to begin with, it will just spoil. So too an older person who is good now it’s because he started out good and got better with time.
Maybe that's what the lesson was for the brothers too. We see that over time Yosef remained good & steadfast in his service of Hashem. Just like aged wine, therefore it must be that he started out good too, and what the brothers thought he did wrong obviously wasn't wrong. Yosef was right!! As now they realized that his dreams did indeed come true. Therefore, even though the Shevatim were so convinced to begin with that what they did was right, with the two words, "Ani Yosef" their world of self righteousness was shattered. Yosef didn't have to rebuke them or even say anything but those two words. Everything was clear to them at that moment. So too says the Chafetz Chaim, at the time of Moshiach, when Hashem says the words, "Ani Hashem" for all the world to hear, the reasons for all our sufferings & long standing Golus will be crystal clear with just the two words of “Ani Hashem."