When the brothers apologise to Yosef, he rebutted this by saying “אַל תִּירָאוּ כִּי הֲתַחַת אלֹהִים אָנִי – “Don’t be afraid, for am I instead of God?” (50:19). It is unclear what exactly he means, but certainly he is not annoyed.
The Baal Haturim suggests that this is is poetic justice as this is precisely what his mother had been told when she begged for children from their father, at which point he said “הֲתַחַת אֱ־לֹהִים אָנֹכִי אֲשֶׁר מָנַע מִמֵּךְ פְּרִי בָטֶן - “Am I instead of God, Who has withheld from you the fruit of the womb?” (30:2)
The Maharil Diskin wonders why a simple yes/no answer isn’t enough, and we can (and have) explained that he did not actually forgive them, but did not say this. We can look deeper into his words: In Parshas Matos (30:7-9) the pasuk describes a woman who makes a vow, but then her husband annuls it. In an event where she did not know he had annulled it, and she thinks she is deliberately breaking it, the pasuk says “‘והֹ יִסְלַח לָהּ“ – “…and the Lord will forgive her.” This is astounding – she has technically done absolutely nothing wrong – her vow had been annulled at the time of her actions, and yet there is a certain something that requires forgiveness! And the same thing was true here:
The brothers thought they had committed a horrendously evil act to their brother, and even though circumstantially it turned out for the best in the end, and the family were reunited – just as in the case of a woman who circumstantially did nothing wrong – there was still a certain something that required forgiveness. The Maharil Diskin suggests an alternate explanation to that which the Baal Haturim suggested, that this is exactly what Yosef was saying here. Due to the turn of events they had done nothing wrong, but he was not in the place of Hashem, because as we said by the woman, they needed G-d’s forgiveness.
In layman’s terms, the ends do not justify the means. Yosef was telling his brothers that they were only circumstantially sorry.
Rabbeinu Bachaye shares a frightening thought that is brilliant. He takes the concept of Yosef not forgiving his brothers a step further, and suggests that this resulted in the Asara Harugei Malchus, one of the greatest tragedies in Jewish history, and one died in lieu of each of the group who’d sold Yosef. Yaakov was not told, as an oath was made as a group of 10 (a minyan) to not tell him, and such an oath cannot be annulled.
But why were there 10 martyrs then, as there weren’t 10 men present at the sale? Binyamin was not there, Reuven had gone home, and we can’t include Yosef as part of such a minyan? There is a concept that a minyan can take place with 9 as Hashem joins in – Hashem was the 10th member of this group.
R’ Shamshon Ostropolier points out that we can expand the pasuk in Bechukosai - “וְכָל מַעְשַׂר בָּקָר וָצֹאן כֹּל אֲשֶׁר יַעֲבֹר תַּחַת הַשָּׁבֶט הָעֲשִׂירִי יִהְיֶה קֹּדֶשׁ לַהֹ – Any tithe of cattle or flock of all that pass under the rod, the tenth shall be holy to the Lord” (27:32)- and there is a deeper meaning to this pasuk, in reference to Rabbi Akiva - וכי למא מת עקיבא, שהוא רואה בקר וצאן הכֹּל אֲשֶׁר יַעֲבֹר תַּחַת הַשָּׁבֶט הָעֲשִׂירִי יִהְיֶה קֹּדֶשׁ לַהֹ – Why did Akiva die? He was just a shepherd! When he passed under the staff (judgement?) he was the tenth, holy for G-d.
There is another allusion to this in Parshas Vayigash (45:15), that “וַיֵּבְךְּ עֲלֵיהֶם – and he cried on them” – we can break up עֲלֵיהֶם and read it על י ה”ם - for the ten Harugei Malchus.
Scary. So not that any of us are like Yosef and his brothers, but it’s clear that we should be more forgiving to people for what they may do to us.