ʿUthmān al-Māzinī, ʿUmar ibn Shabbah, ʿAlī ibn al-Mughīrah al-Athram, Abū al-ʿAynāʾ, and several others.
He lectured in Baghdad on a number of his own works.
Al-Jāḥiẓ said, “No member of the main community nor of the Khārijites anywhere on earth was more knowledgeable in all the sciences than Abū ʿUbaydah.” (1)
Yaʿqūb ibn Shaybah related: “I heard ʿAlī ibn al-Madīnī mention Abū ʿUbaydah; he spoke of him with great praise, validated his transmissions, and said, ‘He never reports anything from the Arabs except what is authentic.’” (2)
Yaḥyā ibn Maʿīn said, “There is nothing objectionable about him.”
Al-Mubarrad remarked, “He and al-Aṣmaʿī were on a comparable level (3) in grammar, yet Abū ʿUbaydah was the most accomplished of them all.” (4)
Ibn Qutaybah observed, “Lexicography and the Days of the Arabs dominated his interests; when he recited a line of poetry he did not scan it correctly, and when he read the Quran from the written text he erred. He disliked the Arabs, wrote books exposing their faults, and inclined to the doctrine of the Khārijites.” (5)
It is also said that Hārūn al-Rashīd summoned Abū ʿUbaydah and read to him some of his writings, which number nearly two hundred. Among them are: the Book of Metaphorical Expressions in the Quran (Kitāb Majāz al-Qurʾān), the Book of Unusual Hadith Expressions (Kitāb Gharīb al-Ḥadīth), and the Book of