Softening The Heart: Kitāb az-Zuhd wa’r-Raqāʾiq

by Abdullah ibn al-Mubarak

Muṭrif narrated that his father said, ‘I came to the Prophet while he was praying, and a wheezing sound like a boiling pot emanated from his chest.’ Meaning he was weeping. (Nasāʾī 1214 and Bayhaqī in as-Sunan al-Kubrā 3357).