‏Shuʿayb ibn Ḥarb said; “There were 4000 of us studying ḥadīth, but none except four became apt.”

‏Abū Dāwūd Sulaymān aṭ-Ṭayālisī said; “I was once at the door of Shuʿbah – whilst the mosque was filled [with students], Shuʿbah then came out, leaned on me and said, ‘Sulaymān, do you think all of them will become scholars of ḥadīth?’ I replied ‘No.’ ‘Correct. Not even five’ [will become scholars of ḥadīth] he said. ‘Not even five!?’ I asked. ‘Yes. one of of them seeks knowledge during his youth, then when he grows up he abandons it. And one of them seeks knowledge during his youth, then when he becomes older he indulges in sin’. Abū Dāwūd Sulaymān aṭ-Ṭayālisī said: ‘he continued to mention other things’ then remarked, “I later investigated and found not even five of them became scholars.”

‏al-Firyābī said; “Sufyān ath-Thawrī said to me one day – whilst people had gathered around him, ‘Muḥammad, do you see all these people? Look how many they are! A third of them will die, a third will abandon this which you hear, and from the remaining third only a few will become highly competent .'”

‏Isrā’īl bin Yunus said; Students of ḥadīth gathered in vast numbers during the time of al-ʿAmash, and so it was said to him; “Abū Muḥammad, do you not see how numerous they are?’ al-ʿAmash replied; Do not look at their numerosity, a third of them will die, a third of them will become busy with work and from every hundred from the [remaining] third, only one will become successful.