[Machine] The Prophet ﷺ passed by Abu Bakr while he was praying and he lowered his voice. He also passed by Umar while he was praying and he raised his voice. When they both gathered in front of the Prophet ﷺ , he said to Abu Bakr, "O Abu Bakr, I passed by you while you were praying and you were lowering your voice?" Abu Bakr replied, "I heard the one I was conversing with." The Prophet ﷺ then said, "O Umar, I passed by you while you were praying and you were raising your voice?" Umar replied, "O Messenger of Allah, I use my voice to keep myself alert." The Prophet ﷺ said to Abu Bakr, "Raise your voice a little." And he said to Umar, "Lower your voice."
أَنَّ النَّبِيَّ ﷺ مَرَّ بِأَبِي بَكْرٍ وَهُوَ يُصَلِّي يَخْفِضُ مِنْ صَوْتِهِ وَمَرَّ بِعُمَرَ وَهُوَ يُصَلِّي رَافِعًا صَوْتَهُ قَالَ فَلَمَّا اجْتَمَعَا عِنْدَ النَّبِيِّ ﷺ قَالَ لِأَبِي بَكْرٍ «يَا أَبَا بَكْرٍ مَرَرْتُ بِكَ وَأَنْتَ تُصَلِّي تَخْفِضُ مِنْ صَوْتِكَ؟» فَقَالَ قَدْ أَسَمِعْتُ مَنْ نَاجَيْتُ فَقَالَ «مَرَرْتُ بِكَ يَا عُمَرُ وَأَنْتَ تَرْفَعُ صَوْتَكَ؟» فَقَالَ يَا رَسُولَ اللَّهِ أَحْتِسَبُ بِهِ أُوقِظُ الْوَسْنَانَ قَالَ فَقَالَ لِأَبِي بَكْرٍ «ارْفَعْ مِنْ صَوْتِكَ شَيْئًا» وَقَالَ لِعُمَرَ «اخْفِضْ مِنْ صَوْتِكَ»