Surah At-Taubah Verse 122 - English Translation by Literal
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 the believers were not to rush/hasten all (to battle) , so if only (there were) a group from every group/party from them, a group of people to learn/comprehend/have knowledge in the religion, and to warn/give notice (to) their nation if they returned to them, maybe/perhaps they be warned/cautioned