Clarification of the Transmission Chain to the Narration of Bilal and the Reward of the mu'adhdhin (callers to prayer)

Everything in this book that is narrated about the story of Bilal and the complete account of the reward of the Mu'adhdhin has been transmitted by me from Ahmad ibn Ziyad ibn Ja'far Al-Hamadani - may Allah (swt) be pleased with him - from Ali ibn Ibrahim ibn Hashim, from his father, from Ahmad ibn Al-Abbas and Al-Abbas ibn Amr Al-Fuqaymi, who both said: Hisham ibn Al-Hakam narrated to us, from Thabit ibn Hurmaz, from Al-Hasan ibn Abi Al-Hasan, from Ahmad ibn Abdul Hamid, from Abdullah ibn Ali, who said