Yazeed bin Rumaan narrates:

Hazrat ‘Uthmaan bin Maz‘oon (radhiyallahu ‘anhu), Hazrat ‘Ubaidah bin Haarith (radhiyallahu ‘anhu), Hazrat Abu ‘Ubaidah bin Jarraah (radhiyallahu ‘anhu), Hazrat ‘Abdur Rahmaan bin ‘Auf (radhiyallahu ‘anhu) and Hazrat Abu Salamah bin ‘Abdil Asad (radhiyallahu ‘anhu) all came together and presented themselves before Rasululah (sallallahu ‘alaihi wasallam). Rasulullah (sallallahu ‘alaihi wasallam) invited them to accept Islam and informed them regarding the injunctions of Islam, after which they all accepted Islam together. All these personalities embraced Islam before they had taken refuge in Daar-e-Arqam.

(Extracted from Seeratul Musatafa 1/168)