What is the clarification of the phrase: "Sufyan ibn Uyaynah narrated to us in his house—I asked him about it—from Salim Abi an-Nadr; then the narration continued and said: or Zayd ibn Aslam, from Ubaydullah ibn Abi Rafi’"? And is it correct to describe Ubaydullah ibn Abi Rafi’ as "the mawla (freed slave) of the Prophet" even though he is not a Companion?

In summary, Sufyan narrated the hadith (definition) to Nasr al-Jahdhami, and Sufyan had narrated this hadith from Salim Abu al-Nadr and Zayd ibn Aslam, both of whom narrated it from Ubayd Allah ibn Abi Rafi'. The hadith is authentic from Sufyan's narration from Salim, and it was narrated by Al-Shafi'i, Ahmad, Al-Tirmidhi, and Al-Hakim. The "mawla (freed slave) of the Prophet - peace and blessings be upon him -" referred to is Abu Rafi', the father of Ubayd Allah, and his name is Aslam.