The Book of Forgetfulness (In Prayer)
13/18. Chapter:
Weeping during prayer
Sunan an-Nasai
أَخْبَرَنَا سُوَيْدُ بْنُ نَصْرٍ، قَالَ أَنْبَأَنَا عَبْدُ اللَّهِ، عَنْ حَمَّادِ بْنِ سَلَمَةَ، عَنْ ثَابِتٍ الْبُنَانِيِّ، عَنْ مُطَرِّفٍ، عَنْ أَبِيهِ، قَالَ أَتَيْتُ النَّبِيَّ صلى الله عليه وسلم وَهُوَ يُصَلِّي وَلِجَوْفِهِ أَزِيزٌ كَأَزِيزِ الْمِرْجَلِ يَعْنِي يَبْكِي .
It was narrated from Mutarrif that his father said: "I came to the Prophet (ﷺ) when he was praying, and there was a sound coming from his chest like the sound of water boiling," meaning, he was weeping.
Reference : Sunan an-Nasa'i 1214In-book reference : Book 13, Hadith 36English translation : Vol. 2, Book 13, Hadith 1215