Ibn Abī al-ʿAwwām relates: My father transmitted to us, saying, “I heard Shuʿayb ibn Ḥarb say:

Sufyān declared, ‘All my life I have wished to spend a single year like Ibn al-Mubārak, yet I cannot manage even three days.’” ⦗1⦘

Muḥammad ibn al-Mundhir reports: Ibrāhīm ibn Baḥr al-Dimashqī told us, saying, ʿImrān ibn Mūsā aṭ-Ṭarasūsī narrated:

A man asked Sufyān, “Where are you from?”
He replied, “From the people of the East.”
The man said, “Do you not have among you the most learned man of the East?”
Sufyān asked, “And who is that?”
He answered, “ʿAbd Allāh ibn al-Mubārak.”
Sufyān responded, “Is he really the most learned of the East?!”
The man said, “Yes—and of the West as well.” ⦗2⦘

Muḥammad ibn al-Mundhir also relates: Muḥammad ibn Aḥmad ibn al-Ḥusayn al-Qurashī told me, saying, Aḥmad ibn ʿAbdah narrated:

Al-Fuḍayl, Sufyān, and a group of elders were sitting in the Sacred Mosque when Ibn al-Mubārak appeared coming up the mountain pass. Sufyān remarked, “Here comes the man of the people of the East.”
Al-Fuḍayl replied, “The man of the people of the East and the West and everything in between.” ⦗3⦘

ʿAlī ibn Zayd reports: ʿAbd al-Raḥmān ibn Abī Jamīl told me:

We were sitting around Ibn al-Mubārak in Mecca and said to him, “O scholar of the East, narrate to us”—while Sufyān was nearby and could hear. He exclaimed, “Woe to you! [Rather], the scholar of the East and the West and all that lies between.” ⦗4⦘

Muḥammad ibn ʿAbd Allāh ibn Quhzādh says: I heard Abū al-Wazīr say, “I visited Sufyān ibn ʿUyaynah, and they said to him, ‘This man is the executor of ʿAbd Allāh’s estate.’ He replied, ‘May Allah have mercy on ʿAbd Allāh; he left no equal to him in Khurāsān.’” ⦗5⦘