Sahih al-Bukhari 1163
In-book no 1163حَدَّثَنَا إِبْرَاهِيمُ بْنُ مُوسَى، أَخْبَرَنَا عِيسَى ـ هُوَ ابْنُ يُونُسَ ـ عَنْ إِسْمَاعِيلَ، عَنِ الْحَارِثِ بْنِ شُبَيْلٍ، عَنْ أَبِي عَمْرٍو الشَّيْبَانِيِّ، قَالَ قَالَ لِي زَيْدُ بْنُ أَرْقَمَ إِنْ كُنَّا لَنَتَكَلَّمُ فِي الصَّلاَةِ عَلَى عَهْدِ النَّبِيِّ صلى الله عليه وسلم، يُكَلِّمُ أَحَدُنَا صَاحِبَهُ بِحَاجَتِهِ حَتَّى نَزَلَتْ {حَافِظُوا عَلَى الصَّلَوَاتِ} الآيَةَ، فَأُمِرْنَا بِالسُّكُوتِ.
Narrated Zaid bin Arqam: In the lifetime of the Prophet (ﷺ) we used to speak while praying, and one of us would tell his needs to his companions, till the verse, 'Guard strictly your prayers (2.238) was revealed. After that we were ordered to remain silent while praying.