مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1729
The Musnad of Ahlul-Bayt & Hadeeth of al-Hasan bin 'Ali bin Abu Talib
It was narrated from Muhammad that al-Hasan bin ‘Ali and Ibn "Abbas saw a funeral; one of them stood up and the other remained seated. The one who stood up said: Didn"t the Messenger of Allah (ﷺ) stand up? The one who remained seated and said: Yes, and he remained seated (sometimes).
Musnad Ahmad 1729Hasan because of corroborating evidence; see the previous re