He memorized one million hadiths. Al-Shafi‘i said of him: “I left Baghdad, and I left behind no one in it more virtuous, more knowledgeable, or more discerning in jurisprudence than Ahmad ibn Hanbal.”

Abu ‘Ubayd said: “Knowledge culminated in four men, the most learned of whom was Ahmad.” Abu Thawr said: “Ahmad was more knowledgeable”—or he said: “more discerning in jurisprudence”—“than al-Thawri.” He died in the year two hundred and forty-one, at the age of seventy-seven.¹

Abu Dawud recorded from him questions in a book comprising jurisprudence, hadith, and the science of narrators, which we shall describe, God willing.

2 — The Imam, the memorizer, the eminent scholar, Abu Zakariyya Yahya ibn Ma‘in al-Murri, client of the Banu Murra, of Baghdad, teacher of al-Bukhari and Muslim. He wrote with his own hands one million hadiths. Ibn al-Madini said: “The knowledge of the people culminated in Yahya ibn Ma‘in.” Ahmad ibn Hanbal said: “Yahya ibn Ma‘in is the most knowledgeable among us concerning narrators.” He died in the year two hundred and thirty-three in Medina.²

Among his most famous teachers in transmission, from whom he narrated extensively and whose narrations he recorded in his book “al-Sunan”:

1 — ‘Abdullah ibn Maslama ibn Qa‘nab al-Qa‘nabi al-Basri, the Imam, the reliable, the exemplar. Al-Bukhari, Muslim, and al-Dhuhli narrated from him. Abu Zur‘a said: “I have not written from anyone more venerable in my eyes than al-Qa‘nabi.” Abu Hatim al-Razi said: “Trustworthy, an authority.”

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¹ Ibn ‘Abd al-Hadi in “Tabaqat ‘Ulama’ al-Hadith” 2/81–83, and al-Dhahabi in “Siyar A‘lam al-Nubala’” 11/177–358.
² Ibn ‘Abd al-Hadi in “Tabaqat ‘Ulama’ al-Hadith” 2/79–81, and al-Dhahabi in “Siyar A‘lam al-Nubala’” 11/71–96.