Secretary or Treasurer of the Holy Prophet (sa)
According to another account, Hazrat Bilal (ra) was the secretary or treasurer of the Holy Prophet (sa).
(Ali Ibn al-Athir, Usd al-Ghabah fi Ma‘rifat al-Sahabah, Vol. 1, Bilal bin Rabah [Beirut, Lebanon: Dar al-Kutub al-Ilmiyyah, 2008] 415)
A person once asked Hazrat Ibn Abbas (ra), “Did you also accompany the Holy Prophet (sa) in any journey?” He replied, “Were it not for my relationship with the Holy Prophet (sa), I would not have been able to participate in any journey with him.” What he meant by this is that he had the opportunity to travel because he was young and also due to the fact that he was related to the Holy Prophet (sa).
He further states, “The Holy Prophet (sa) then arrived near the sign which was close by the house of Hazrat Kathir bin Salt (ra) and delivered an address to the companions. He then went to the women and granted them some advice and instructed them to give alms. The women then lowered their hands to remove their rings and one by one they placed them in the cloth of Hazrat Bilal (ra) (Hazrat Bilal (ra) was with the Holy Prophet(sa) at the time).” This is the account of Hazrat Ibn Abbas (ra). Thereafter, the Holy Prophet (sa) and Hazrat Bilal (ra) returned home.
(Sahih al-Bukhari, Kitab al-Adhan, Bab Wudu al-Sibyan wa mata Yajibu ‘alaihim al-Ghusl…, Hadith 863)
Hazrat Anas bin Malik (ra) states, “The Holy Prophet (sa) told me, ‘I have suffered so much affliction for the sake of Allah, which no other person can be given. I have been threatened so much for the sake of Allah that no other person can be threatened to that extent. Three nights would pass whereby no food would be brought to me and Bilal (ra), which was edible, except that which could be hidden under the arm of Bilal (ra) (i.e., they only had very little food).”
(Sunan Ibn Majah, Fada‘il Bilal, Hadith 150, Noor Foundation translation)