It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that he used to walk in front of the funeral procession, and the Messenger of Allah (peace and blessings be upon him), Abu Bakr, Umar and Uthman (may Allah be pleased with them) also used to walk in front of it.
(Imam Ahmad bin Hanbal (may Allah have mercy on him) said about this hadith: It is mursal from al-Zuhri, while the narration of Salim is based on Ibn Umar's (may Allah be pleased with them both) own practice, and in the narration of Ibn Uyaynah it seems an error occurred.)
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13077