37 – ʿUthmān (may Allah be pleased with him) said: “The Prophet—peace and blessings be upon him—used to run his fingers through his beard during ablution.” It was recorded by al-Tirmidhī, and Ibn Khuzaymah declared it sound. (1)
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Hadith grading:
The report is weak, yet it has supporting chains from many Companions. Each of those chains is open to some critique, but taken together they strengthen one another.
Al-Ḥāfiẓ Ibn Ḥajar states in al-Talkhīṣ: “It was transmitted by al-Tirmidhī, Ibn Mājah, Ibn Khuzaymah, al-Ḥākim, al-Dāraquṭnī and Ibn Ḥibbān on the authority of ʿUthmān, and al-Ḥākim produced corroborations from Anas, ʿĀ’ishah, ʿAlī and ʿAmmār.”
I add: reports also exist from Umm Salamah, Abū Ayyūb, Abū Umāmah and others. Al-Ḥāfiẓ lists them in al-Talkhīṣ, together with their routes and chains.
Al-Kattānī and al-Suyūṭī ranked the ḥadith among the mass-transmitted traditions, noting that it is related by eighteen Companions. Even so, several hadith critics—among them al-ʿUqaylī, Ibn Ḥazm and al-Zaylaʿī—judged the isnāds concerning passing water through the beard to be weak.
Imām Aḥmad and Abū Ḥātim said, “Nothing sound has been established about running the fingers through the beard.”

Lexical note:
– His beard: liḥyah (the hair of the cheeks and chin); plural liḥā, with the initial lām pronounced either with a kasrah or a ḍammah.

Points derived from the hadith:
1 – The practice of running the fingers through the beard during ablution is recommended. It consists of parting the hair and letting the water flow between the strands so that the water of ablution reaches the skin beneath.