Bismillah wa salatu wa salamu ala rasulallah.
Ibn Sad reported in Tabaqat al-Kabir (3/16-17, TaHa Publishers):
Yazid ibn Haroon reported from Ismail ibn Abi Khalid that ash-Shabi said: I saw Ali. He had a large beard which filled all that was between his shoulders..”.
al-Fadl ibn Dukayn reported from Yunus ibn Abi Ishaq that his father Abu ismail said: I saw Ali and my father said to me: Amr look at the commander of faithful. I went to him and I saw that he did not dye his beard. He had a large beard“.
Shihab ibn Abbad al-Abdi reported from Ibrahim ibn Humayd from Ismail that Amir said: I have never seen a man with a larger beard than Ali. It filled the space between his shoulders and was white.
al-Fadl ibn Dukayn reported that Rizam ibn Sad ad-Dabbi heard his father describing Ali, he said: A man taller than medium with large shoulders and a long beard..