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 Messengerof Allah, may Allah bless him and grant him peace, and Abu Bakr andUmar as well as the khalifas up until this time and Abdullah ibn Umar,would walk in front of the bier. Translation Not Available

Book Ref: Muwatta Imam Malik Book 16 Hadith 530
Web Ref:  Muwatta Imam Malik Book 16 Hadith 8