Surah At-Taubah Verse 122 - English Translation by Muhammad Mahmoud Ghali
Surah At-Taubah۞وَمَا كَانَ ٱلۡمُؤۡمِنُونَ لِيَنفِرُواْ كَآفَّةٗۚ فَلَوۡلَا نَفَرَ مِن كُلِّ فِرۡقَةٖ مِّنۡهُمۡ طَآئِفَةٞ لِّيَتَفَقَّهُواْ فِي ٱلدِّينِ وَلِيُنذِرُواْ قَوۡمَهُمۡ إِذَا رَجَعُوٓاْ إِلَيۡهِمۡ لَعَلَّهُمۡ يَحۡذَرُونَ
And in no way should the believers march out, as a whole; so, had only a section of every grouping marched out, (another section would have stayed) to comprehend for themselves in the religion, (i.e., to study the religion) and to warn their people when they return to them, that possibly they would beware