التفسير التبليغي
(He) said: "Do you know what you did to Joseph and his brother when you were ignorant?" (89)
The lessons had concluded, and the time had come for the great surprise that had not crossed their minds.
Here, he immediately revealed his identity... he lifted the veil, the curtain was removed.
He did not wish to reveal his identity to them except at the appropriate time.
Now, when he saw that they were prepared for repentance, he wanted to reveal his identity to them.
When he saw that the matter had reached its peak, he made himself known to them.
The critical hour... a subtle stratagem.
When they reached this extent of pleading, distress, and brokenness, Joseph no longer had the ability to continue playing the role of the Aziz (governor) and concealing his true identity from them.
He felt compassion for them after seeing their tears flow.
When they sought his compassion, he softened towards them and had mercy on them.
Now they were ready for repentance... his objective was achieved.
Souls were now prepared for frankness: ("He) said: 'Do you know what you did to Joseph?'"
("Do you know what you did?") The interrogative is used for reproof.
He disclosed the bitter truth to them and took them back to the distant past which only they knew, and which no one had witnessed except Allah.
He did not say: "What crime did you commit against Joseph?!" Rather, he said: ("Do you know what you did to Joseph?")
Joseph (peace be upon him) was required to perform an ethical epic to elevate his brothers to the level of planets and stars.
Through effort, the reality of religion comes to you, and through your good character, guidance comes to people.
Estrangement and harshness between brothers... despite everything that happened, no bad word would escape from the noble Joseph, which would lower him from his elevated self.
("He) said: 'Do you know what you did to Joseph and his brother when you were ignorant?'" He did not say: "oppressors"!!!
("when you were ignorant") This was a word he chose carefully to preserve the bond of affection between them amidst the bitter frankness that revealed what the years had hidden, and perhaps what their forgetfulness had hidden, but which his memory had not hidden.
("when") meaning: at the time ("you were ignorant") reminding them of the sin so they might repent.
("when you were ignorant") meaning: young, heedless individuals.
It was said: He only meant the ignorance of youth, not the ignorance of sins.
("when you were ignorant") meaning: Do you know the ugliness of what you did in your time of ignorance?
It was said: The intention is that they were ignorant of what the outcome of the matter would be.
It was not gloating, but rather an urging to desist (from sin) and an advice to them, given the helplessness and humility he witnessed in them.
He made that time the time of their ignorance by saying ("when you were ignorant"), and this implies that their condition had improved thereafter.
Source: التفسير التبليغي