Who is Abu Ishaq al-Hamadani, what are his contributions to hadith, and what is the authenticity of his hadith?

Abu Ishaq al-Hamdani (Amr ibn Abdullah al-Sabi'i) was one of the great memorizers and scholars of Kufa. He was born in the year 34 or 35 AH and met many Companions (Sahaba) from whom he narrated. The number of his shaykhs reached into the hundreds. He was renowned for his leadership in religion, piety, asceticism, and worship. He would complete a full recitation of the Qur'an every three days and participated in jihad. He was a constant keeper of fasts and performer of night prayers (qawwam), and would recite a thousand verses every night. He was characterized by great manners and humility. Imams of Hadith (definition), such as Shu'ba and Sufyan al-Thawri, learned from him. His scholarly and practical contributions continued for 93 years. His eyesight weakened in his later years, but his memory remained unimpaired. He passed away in the year 127 AH.