Sunan an-Nasai Book 21, Hadith 1927

أَخْبَرَنَا إِبْرَاهِيمُ بْنُ هَارُونَ الْبَلْخِيُّ، قَالَ حَدَّثَنَا حَاتِمٌ، عَنْ جَعْفَرِ بْنِ مُحَمَّدٍ، عَنْ أَبِيهِ، أَنَّ الْحَسَنَ بْنَ عَلِيٍّ، كَانَ جَالِسًا فَمُرَّ عَلَيْهِ بِجَنَازَةٍ فَقَامَ النَّاسُ حَتَّى جَاوَزَتِ الْجَنَازَةُ فَقَالَ الْحَسَنُ إِنَّمَا مُرَّ بِجَنَازَةِ يَهُودِيٍّ وَكَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم عَلَى طَرِيقِهَا جَالِسًا فَكَرِهَ أَنْ تَعْلُوَ رَأْسَهُ جَنَازَةُ يَهُودِيٍّ فَقَامَ ‏.‏

It was narrated from Ja'far bin Muhammad from his father that:Al-Hasan bin 'Ali was sitting when a funeral passed by. The People stood until the funeral had passed, and Al-Hasan said: "The funeral of Jew passed by when the Messenger of Allah was sitting in its path, and he did not want the funeral of a Jew to pass over his head, so he stood up