The first narration is as follows:

When Hazrat Abu Zar (radhiyallahu ‘anhu) had neared his end, there was nobody with him besides his wife and slave. He instructed them saying, “Give me ghusl and enshroud me in the kafn (when I pass away). Then take my body and place it on the road. Say to the first caravan passing by, “This is Abu Zar (radhiyallahu ‘anhu), the companion of Rasulullah (sallallahu ‘alaihi wasallam). Help us and assist us to bury him.” When he passed away, they both gave him ghusl and enshrouded him and thereafter placed his body on the road. The first caravan to pass by was that of Hazrat Abdullah bin Mas‘ood (radhiyallahu ‘anhu). He was on his way to Makkah Mukarramah to perform Umrah with a caravan of people from Iraq. As they were passing by, they were surprised to see a body lying on the road and it was feared that the camels would trample it. At that point, the slave of Hazrat Abu Zar (radhiyallahu ‘anhu) came forward and said to them, “This is Hazrat Abu Zar (radhiyallahu ‘anhu), the companion of Nabi (sallallahu ‘alaihi wasallam). Help us to bury him.” On hearing this, Hazrat Abdullah (radhiyallahu ‘anhu) began to weep and said, “Rasulullah (sallallahu ‘alaihi wasallam) spoke the truth when he said, “O Abu Zar! You have come walking alone, you will pass away alone and you will be resurrected alone.”” They then descended from their camels and proceeded to bury him. Nabi (sallallahu ‘alaihi wasallam) had mentioned this on the occasion of Tabook.

(Ibn Sa’d 4/177)