So when they took him [out] and agreed to put him into the bottom of the well... But We inspired to him, "You will surely inform them [someday] about this affair of theirs while they do not perceive [your identity]."
The Saheeh International Quran Translation
فَلَمَّا ذَهَبُوا۟ بِهِۦ وَأَجْمَعُوٓا۟ أَن يَجْعَلُوهُ فِى غَيَٰبَتِ ٱلْجُبِّ وَأَوْحَيْنَآ إِلَيْهِ لَتُنَبِّئَنَّهُم بِأَمْرِهِمْ هَٰذَا وَهُمْ لَا يَشْعُرُونَSo when they took him [out] and agreed to put him into the bottom of the well... But We inspired to him, "You will surely inform them [someday] about this affair of theirs while they do not perceive [your identity]."