Sa'īd al-Ansārī; Rabī'a ibn Abī 'Abd al-Rahmān; Hanzala ibn Abī Sufyān al-Jumahī; 'Abd al-'Azīz ibn Abī Salama al-Mājishūn; and others. Abū Yūsuf used to attend their gatherings and learn hadith from them, acquiring much from those who came from the Hijaz.

Thus, it is said of Abū Hanīfa’s companions that Abū Yūsuf was the most knowledgeable in hadith; Zufar was the most consistent in applying analogical reasoning; al-Hasan ibn Ziyād al-Lu'lu'ī was the most prolific in elaborating subsidiary rulings; and Muhammad was the most knowledgeable in Arabic and arithmetic. Sometimes Muhammad was also described as the most prolific in elaborating subsidiary rulings.

When Iraq became the seat of government, and it became necessary to acquaint its inhabitants with the Sunnah and the revealed Law, the legally prescribed measure was recalibrated using the Iraqi ratl. Their ratl, measured in dense wheat and lentils, was then ninety mithqāls: 128 dirhams and four-sevenths of a dirham. This, then, is the first level of the consensus of the people of Medina, and it constitutes authoritative evidence by agreement of the Muslims.

The Second Level

The early practice in Medina before the killing of 'Uthmān ibn 'Affān constitutes authoritative evidence in Mālik’s school. This is also al-Shāfi'ī’s expressly stated position. As reported by Yūnus ibn 'Abd al-A'lā, he said:

“If you find the early generations of the people of Medina agreed upon something, entertain no doubt in your heart that it is the truth.”

Likewise, the apparent position of Ahmad’s school is that whatever the Rightly Guided Caliphs instituted constitutes authoritative evidence that must be followed. Ahmad said:

“Every pledge of allegiance given in Medina established a caliphate on the prophetic model.”

It is well known that the pledges of allegiance to Abū Bakr, 'Umar and 'Uthmān were given in Medina. Likewise, the pledge of allegiance to 'Alī was given in Medina; he subsequently left it, and thereafter no pledge of allegiance was concluded in Medina.