al-Nadr bin Shumayl al-Maazni النضر بن شميل المازني أبو الحسن النحوي · The Book of Funerals

a funeral passed by Al-Hasan bin 'Ali and Ibn 'Abbas. Al-Hasan stood up but Ibn 'Abbas did not/ Al-Hasan said: 'Didn't the Messenger of Allah stand up for the funeral of a Jew?' Ibn 'Abbas said: 'Yes, then he sat down."'