Sunan an-Nasai 15952
In-book no 1216أَخْبَرَنَا 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.