He never met ʿAmr ibn ʿUbayd; instead, he kept close company with the latter’s disciple, ʿUthmān ibn Khālid al-Ṭawīl.
It is also said that he was a client (mawlā) of the tribe of ʿAbd al-Qays.

When the theologian Ṣāliḥ ibn ʿAbd al-Quddūs lost a son, al-ʿAllāf went to console him and found him deeply distressed. He asked, “Why this grief, when you hold that man is like a crop in the field?”
Ṣāliḥ replied, “Abū al-Hudhayl, I sorrow for him only because he never read my Kitāb al-Shukūk (The Book of Doubts). Whoever reads it will doubt what has actually occurred until he imagines it never happened, and will doubt what has never occurred until he thinks it did happen.”
Abū al-Hudhayl retorted, “Then harbour doubt about your son’s death—suppose he has not died—and doubt whether he may, after all, have read The Book of Doubts.”

Abū al-Hudhayl composed a treatise refuting the Magians, another refuting the Jews, a third refuting the anthropomorphists, one against the atheists, and yet another against the Sophists; he authored many other works as well, but none of them have survived.

76 – Ibn Kullāb, ʿAbd Allāh ibn Saʿīd al-Qaṭṭān al-Baṣrī *
He was the leading theologian (mutakallim) of Basra in his day: Abū Muḥammad ʿAbd Allāh ibn Saʿīd ibn Kullāb al-Qaṭṭān, the Basran, author of treatises refuting the Muʿtazila—though at times he agreed with them.

Dāwūd al-Ẓāhirī studied kalām under him, as reported by Abū al-Ṭāhir al-Dhuhlī. It is also said that al-Ḥārith al-Muḥāsibī learned the science of dialectical reasoning from him.

He was nicknamed “Kullāb” because, through his clarity and eloquence, he would “pull” his opponent over to his side. His followers are known as the Kullābiyya; some of them were later joined by Abū al-Ḥasan al-Ashʿarī. They were noted for their refutation of the Jahmiyya.