In 776/7, he campaigned against Yusuf al-Barm in Khurasan.[2] Sa'id was a close friend and boon-companion of Caliph al-Hadi (r. 785–786).[3] He was with al-Hadi at Jurjan when news came of the death of his father, Caliph al-Mahdi, and al-Hadi's accession; together the two rode for Baghdad, where al-Hadi ascended the throne.[4] According to an account preserved by al-Tabari, Sa'id held the highest rank at court under al-Hadi, succeeding his own brother Ibrahim.[5]