Mutarrif b. ‘Abdallah [b.] ash-Shikhkhir quoted his father as saying, “I came to the Prophet when he was engaged in prayer, and heard a sound from within him like the bubbling of a pot,” meaning that he was weeping. In a version he said, “I saw the Prophet praying and a sound came from his breast like the rumbling of a mill, owing to weeping.” Ahmad transmitted it. Nasa’i transmitted the first version and Abu Dawud the second.
Hadith Referenceمشكوة المصابيح / كتاب الصلاة / 1000
Hadith Gradingالألبانی:صَحِيح | زبیر علی زئی:إسناده صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «إسناده صحيح، رواه أحمد (4/ 25 ح 16421) والنسائي (13/3 ح 1215) و أبو داود (904) [و صححه النووي في رياض الصالحين (451) بتحقيقي .]»