Ibn alQayyim said,
And the Religion, Fiqh, and knowledge spread between the people from the companions of Ibn Masud, the companions of Zayd bin Thabit, the companions of Abdullah bin Umar, and the companions of Abdullah bin Abbas. So, all the knowledge that is with the people is generally from the companions of these four.
As for the people of Madinah, their knowledge is from the companions of Zayd bin Thabit and Abdullah bin Umar.
As for the people of Makkah, their knowledge is from the companions of Abdullah bin Abbas.
As for the people of Iraq, their knowledge is from the companions of Abdullah bin Masud.
Ibn Jarir said, 'It has been said that Ibn Umar and a group of the Messenger of Allahs Companions who lived after him in Madinah would issue verdicts based on the madhhab of Zayd bin Thabit and the knowledge they had acquired from him that was not addressed by what they had learned from the Messenger of Allah's words.'
Abd ArRahman bin Zayd bin Aslam said, 'When the Abdullahs died ,Abdullah bin Abbas, Abdullah bin AzZubayr, and Abdullah bin Amr bin alas. All the knowledge that was present in all the lands was left in the hands of their servants. So, the scholar of people of Makkah was Ata bin Abi Rabah, the scholar of Yemen was Tawus, the scholar of Yamamah was Yahya bin Abi Kathir, the scholar of Kufah was Ibrahim, the scholar of Basrah was AlHasan, the scholar of Sham was Makhul, and the scholar of Khurasan was Ata AlKhurasani. All except Madinah, as Allah had reserved this position for a Qurashi. So, the scholar of Madinah was Said bin AlMusayyab, without dispute.
Said bin AlMusayyab said,'I passed by Abdullah bin Umar. So, I greeted him and went on my way. I then turned and looked at all of his companions, and he said, 'If the Messenger of Allah had seen this, it would have made him very happy,' and he raised his hands and pointed them to the sky.'
And Said bin AlMusayyab would stay up all night with Abu Hurayrah, and he married Abu Hurayrahs daughter. When he saw him, he would say, 'I ask Allah to gather you and I in the marketplaces of Paradise,' and this is why he narrated in abundance from him.
Ilam alMuwaqqiin 1/17,18



