Mishkat al-Masabih
Mishkat al-Masabih 157
وَعَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «مَا من نَبِي بَعثه الله فِي أمة قبلي إِلَّا كَانَ لَهُ من أُمَّتِهِ حَوَارِيُّونَ وَأَصْحَابٌ يَأْخُذُونَ بِسُنَّتِهِ وَيَقْتَدُونَ بِأَمْرِهِ ثُمَّ إِنَّهَا تَخْلُفُ مِنْ بَعْدِهِمْ خُلُوفٌ يَقُولُونَ مَا لَا يَفْعَلُونَ وَيَفْعَلُونَ مَا لَا يُؤْمَرُونَ فَمَنْ جَاهَدَهُمْ بِيَدِهِ فَهُوَ مُؤْمِنٌ وَمَنْ جَاهَدَهُمْ بِلِسَانِهِ فَهُوَ مُؤْمِنٌ وَمَنْ جَاهَدَهُمْ بِقَلْبِهِ فَهُوَ مُؤْمِنٌ وَلَيْسَ وَرَاءَ ذَلِكَ مِنَ الْإِيمَانِ حَبَّةُ خَرْدَلٍ» . رَوَاهُ مُسلم
ʿAbd Allah ibn Masʿud reported that the Messenger of God said: ‘There was no prophet whom God sent among a people before me but that he had among his community devoted followers and companions who held to his Sunnah and followed his command. Then after them came successors who said what they did not do and did what they were not commanded to do. Whoever strives against them with his hand is a believer; whoever strives against them with his tongue is a believer; and whoever strives against them with his heart is a believer. Beyond that, there is not even a mustard seed’s worth of faith.’ Muslim transmitted it.