مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 409
Purification
How to Perform Ablution - Section 2
وَعَنْ عُثْمَانَ رَضِيَ اللَّهُ عَنْهُ: أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يُخَلِّلُ لِحْيَتَهُ. رَوَاهُ التِّرْمِذِيّ والدارمي
‘Uthman said that the Prophet (ﷺ) used to make the water go through his beard. Tirmidhi and Darimi transmitted it.
Mishkat al-Masabih, 409لم تتمّ دراسته (الألباني)