Jabir ibn Abdullah reported: Mu’adh ibn Jabal used to pray with the Prophet, peace and blessings be upon him. Then, he returned to his people and led them in prayer. Mu’adh prayed the evening prayer and recited Surat al-Baqarah, until a man left the prayer and Mu’adh was critical of him. The news reached the Prophet and he said three times, “You put them to trial!” The Prophet ordered him to recite two medium chapters from the end of the Quran (al-mufassal).
Source: Ṣaḥīḥ al-Bukhārī 669
Grade: Sahih (authentic) according to Al-Bukhari
عن جَابِر بْن عَبْدِ اللَّهِ قَالَ كَانَ مُعَاذُ بْنُ جَبَلٍ يُصَلِّي مَعَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ثُمَّ يَرْجِعُ فَيَؤُمُّ قَوْمَهُ فَصَلَّى الْعِشَاءَ فَقَرَأَ بِالْبَقَرَةِ فَانْصَرَفَ الرَّجُلُ فَكَأَنَّ مُعَاذًا تَنَاوَلَ مِنْهُ فَبَلَغَ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ فَتَّانٌ فَتَّانٌ فَتَّانٌ ثَلَاثَ مِرَارٍ وَأَمَرَهُ بِسُورَتَيْنِ مِنْ أَوْسَطِ الْمُفَصَّلِ
669 صحيح البخاري كتاب الأذان باب إذا طول الإمام وكان للرجل حاجة فخرج فصلى