He was an ocean of knowledge.

Mūsa ibn Nuṣayr said, “I heard him declare: ‘I met one thousand seven hundred shaykhs—the youngest of them was ʿAbd al-Razzāq—and I spent, in the pursuit of knowledge, seven hundred thousand dirhams.’ (1)

Abū Ḥātim remarked, ‘He is truthful (2); I have never seen anyone of greater stature or more illustrious than Hishām ibn ʿUbayd Allah in Rayy, or Abū Mushir al-Ghassānī in Damascus.’

As for Ibn Ḥibbān, he considered him weak and produced for him a report that cannot be accepted, narrated by Ibn Abī Dhīb from Nāfiʿ from Ibn ʿUmar, traced back to the Prophet: ‘Chicken is the sheep of the poor among my community, and Friday is their pilgrimage.’ (3)

Shaykh Abū Isḥāq states in Tabaqāt al-Ḥanafiyyah: ‘He is weak in transmission, and Muḥammad ibn al-Ḥasan died in his house.’ (4)

Muḥammad ibn Khalaf al-Kharrāz related: “I heard Hishām ibn ʿUbayd Allah al-Rāzī say, ‘The Quran is the Speech of Allah, uncreated.’ A man asked him, ‘Does not Allah say, “No reminder ever comes to them from their Lord that is newly revealed”?’ He replied, ‘It is new in relation to us, but with Allah it is not new.’

I say: That is because it is part of Allah’s knowledge, and the knowledge of Allah is not described as originated.

He died in 221 AH, as dated by ʿAbd al-Raḥmān ibn Muḥammad al-ʿAbdī.