(18) باب الْبُكَاءِ فِي الصَّلاَةِ
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. (DE)
Reference (DE): Sunan an-Nasa'i 1214 (DE)
In-book reference (DE): Book 13, Hadith 36 (DE)
English translation (DE): Vol. 2, Book 13, Hadith 1215 (DE)