Those who narrated from him include: al-Bukhari, Muslim, Abu Dawud, Abu Zurʿah, Ibrahim al-Harbi, Abu Hatim, ʿAbd Allah ibn Ahmad, Baqi ibn Makhlad, Jaʿfar al-Firyabi, Abu Yaʿla al-Mawsili, Abu Bakr Ahmad ibn ʿAli al-Marwazi, Salih ibn Muhammad Jazrah, and many others besides them.
Among those who committed his hadith to writing were Yahya ibn Maʿin, Ahmad ibn Hanbal, and Ibn Saʿd.
Yahya [ibn Maʿin], the ḥāfiẓ Salih Jazrah, and al-Nasaʾi all graded him reliable.
Ibn Saʿd said, “Trustworthy, with an abundant collection of hadith.”
Abu Hatim said, “Truthful.”
Ahmad ibn Sayyar remarked, “Of everyone I have met, I have not seen anyone like Musaddad in Basra, al-Qawārīrī in Baghdad, and Sadaqah ibn al-Fadl in Marw.”
ʿAbd al-Muʾmin ibn Khalaf related: “I heard Salih ibn Muhammad say, ‘Al-Qawārīrī is more firmly accurate than al-Zahrani (1), more renowned, and more knowledgeable in the hadith of Basra. I have never encountered anyone more learned in the hadith of Basra than he—apart from ʿAli, meaning Ibn al-Madini, and Ibrahim ibn ʿArʿarah.’”
He also said, “I heard al-Qawārīrī declare, ‘I have never seen Abu al-Rabiʿ in Hammad’s company at all.’”
Ibn al-Anbari stated: “I heard Thaʿlab say, ‘I received one hundred thousand hadiths from ʿUbayd Allah al-Qawārīrī.’”
Ibn ʿAllan informed us; al-Kindi informed us; al-Qazzaz informed us; al-Khatib informed us; Ibn Rizquwayh informed us: I heard ʿAli ibn al-Hasan ibn Zakariyya al-Qatiʿi, the poet, say, “I heard Abu….”