That is from the news of the unseen which We reveal, [O (12:102)

﴿ذَٰلِكَ مِنْ أَنبَاءِ الْغَيْبِ نُوحِيهِ إِلَيْكَ ۖ وَمَا كُنتَ لَدَيْهِمْ إِذْ أَجْمَعُوا أَمْرَهُمْ وَهُمْ يَمْكُرُونَ﴾
[ يوسف: 102]

12:102 That is from the news of the unseen which We reveal, [O Muhammad], to you. And you were not with them when they put together their plan while they conspired.

Allah revealed all that has been mentioned from the story of Joseph and his brothers to the Messenger ( peace be upon him ).
He had no knowledge of it beforehand, since he was not there with the brothers of Joseph when they agreed to throw him into the bottom of a well, and when they planned their trick; but Allah revealed this all to the Messenger ( peace be upon him ).

This is of the news of the Ghaib (unseen) which We reveal by Inspiration to you (O Muhammad SAW). You were not (present) with them when they arranged their plan together, and (also, while) they were plotting.

phonetic Transliteration

Thalika min anbai alghaybi nooheehi ilayka wama kunta ladayhim ith ajmaAAoo amrahum wahum yamkuroona

Abdullah Yusuf Ali - Translation

Such is one of the stories of what happened unseen, which We reveal by inspiration unto thee; nor wast thou (present) with them then when they concerted their plans together in the process of weaving their plots.

Safi-ur-Rahman al-Mubarakpuri

That is of the news of the Ghayb (Unseen) which We reveal to you. You were not (present) with them when they arranged their plan together, and (while) they were plotting.

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