Surah At-Taubah Verse 122 - English Translation by Syed Vickar Ahamed
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 it is improper for (all) the believers to go away together (for Jihad). A (small) section from every expedition should remain behind, so they could devote themselves to studies in religion, and warn the people when they returned to them— That, thus they may guard themselves (against evil)