Aḥmad ibn ʿAbd al-Aʿlā al-Shaybānī related: Abū Yaʿqūb al-Madani told me:
“There arose some ill feeling between Ḥasan ibn Ḥasan and his cousin ʿAlī ibn al-Ḥusayn. Ḥasan left nothing unsaid; he voiced every grievance, while ʿAlī remained silent. Ḥasan then went his way. Later that night ʿAlī came to him, so he stepped outside. ʿAlī said, ‘My cousin, if what you said was true, may Allah forgive me; and if it was false, may Allah forgive you. Peace be upon you.’ Ḥasan embraced him and wept until one felt pity for him. (1)

Abū Nuʿaym said: ʿĪsā ibn Dīnār—a trustworthy narrator—told us:
“I asked Abū Jaʿfar about al-Mukhtār. He replied, ‘My father once stood at the gate of the Kaʿbah and cursed al-Mukhtār.’ People objected, ‘You curse him even though he was slain on your behalf?’ He answered, ‘He used to lie against Allah and His Messenger.’ (2)

Al-Ḥakam reports from Abū Jaʿfar:
‘We pray behind them—meaning the Umayyads—without resorting to taqiyyah (precautionary dissimulation), and I testify that my father also prayed behind them without taqiyyah.’ (3)
This was transmitted by Abū Isrāʾīl al-Mulāʾī on his authority.

ʿUmar ibn Ḥabīb narrated, from Yaḥyā ibn Saʿīd:
ʿAlī ibn al-Ḥusayn said, ‘By Allah, ʿUthmān—may Allah be pleased with him—was not killed justly.’ (4)

More than one source records that ʿAlī ibn al-Ḥusayn used to dye his beard with henna and katam.
It is also said that he owned a yellow cloak which he would wear on Fridays. (5)