Abu Ahmad al-Hakim: He was a Companion
Ahmad ibn Shuayb al-Nasai: Trustworthy
Ibn Hajar al-Asqalani: A Companion who led a delegation
al-Dhahabi: His companionship is disputed
al-Mizzi: His companionship is disputed
Muhammad ibn Ismail al-Bukhari: He was a Companion
Muhammad ibn Saad, the scribe of al-Waqidi: A Jahili [pre-Islamic Arab] who became Muslim and met the Prophet, peace and blessings be upon him, and embraced Islam