Musnad Abu Ya'la al-Mawsili 151:72

Na'im ibn Haysam narrated to us, Khalid—meaning al-Wasiti—narrated to us, from Yahya al-Jabir, from Abu Majidah, from Ibn Mas'ud, who said: We asked our Prophet (ﷺ) about walking with the funeral procession. He said: "It should be at a pace less than a trot. If it is good, it is being hastened toward; and if it is otherwise, then it is a distancing for the people of the Fire." The funeral procession is to be followed and is not to be followed [by others]. Whoever precedes it is not of it.