Hadith 505300
Chapter 16: Burials - كتاب الجنائز
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم وَأَبَا بَكْرٍ وَعُمَرَ كَانُوا يَمْشُونَ أَمَامَ الْجَنَازَةِ وَالْخُلَفَاءُ هَلُمَّ جَرًّا وَعَبْدُ اللَّهِ بْنُ عُمَرَ .
Yahya related to me from Malik from Ibn Shihab that the Messenger of Allah, may Allah bless him and grant him peace, and Abu Bakr and Umar as well as the khalifas up until this time and Abdullah ibn Umar, would walk in front of the bier.
Reference Muwatta Malik 505300
USC-MSA web (English) reference : Book 16, Hadith 8