The Book of Funerals
21/47. Chapter:
Concession Allowing One To Not Stand Up
Sunan an-Nasai
أَخْبَرَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، عَنِ ابْنِ عُلَيَّةَ، عَنْ سُلَيْمَانَ التَّيْمِيِّ، عَنْ أَبِي مِجْلَزٍ، عَنِ ابْنِ عَبَّاسٍ، وَالْحَسَنِ بْنِ عَلِيٍّ، مَرَّتْ بِهِمَا جَنَازَةٌ فَقَامَ أَحَدُهُمَا وَقَعَدَ الآخَرُ فَقَالَ الَّذِي قَامَ أَمَا وَاللَّهِ لَقَدْ عَلِمْتُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَدْ قَامَ قَالَ لَهُ الَّذِي جَلَسَ لَقَدْ عَلِمْتُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَدْ جَلَسَ .
It was narrated from Ibn 'Abbas and Al-Hasan bin 'Ali that: a funeral passed by them and one of them stood and the other sat. The one who stood up said: "By Allah, I know that the Messnger of Allah stood up." The one who was sitting said: "I know that the Messenger of Allah sat."
Reference : Sunan an-Nasa'i 1926In-book reference : Book 21, Hadith 109English translation : Vol. 3, Book 21, Hadith 1927