The city of Kufa is called the city of knowledge

 

Hazrat Omar  When the city of Kufa was founded during his caliphate, he chose Abdullah Ibn Mas'ud as the teacher of the Qur'an and Sunnah of that city and wrote a decree for the inhabitants of Kufa, 'I made Ammar the Amir and Abdullah Ibn Mas'ud the Wazir and Teacher.  Made and sent to you.  Both of them participated in the Battle of Badr and were among the prestigious Companions of the Prophet (peace be upon him).  Will be loyal to them and follow them.  I needed Abdullah, but I prioritized your needs over mine.'

 Abdullah Ibn Masud came to the city of Kufa.  He channeled the fountains of knowledge and created as his successor a personality that was unmatched even in his time.

 The city of Kufa is more fortunate that during the caliphate of Hazrat Ali, it was the 'Darul Khilafah' i.e. the capital.  And Ali Ra.  It has been said that, 'He is the gate of the city of knowledge', so his arrival enriched the city as a center of knowledge.  However, Hazrat Abdullah Ibn Masood RA was at the top among the Companions who initiated and developed the knowledge of Quran and Sunnah in this city.  Other Companions also considered the position of Abdullah Ibn Mas'ud as sufficient for the knowledge and virtue of the people of Kufa.  Still the scholars of Kufa were in the habit of enriching their knowledge by visiting other centers of knowledge.

Abdallah ibn Mas'ud, the prominent disciple of Alkama.  Said, I appeared in the majlis of Abuddarda RA.  He asked me, where are you from?  I said, from Kufa.  He then said, "Isn't Ibn Umm Abd staying there, who is the carrier of the Prophet's bed, miswak and shoes, who is also aware of the Prophet's private affairs and who was declared free from Satan by the Prophet?"  -Sahih Bukhari 7/71, 73

 Hazrat Ali RA  When he arrived in Kufa, Abdullah Ibn Mas'ud's disciples were the Ustads and Mu'allim of the city.  Seeing their involvement in the spread of knowledge, Hazrat Ali RA.  He said, 'Ibn Umm Abd made a lamp of kufr for them and left.' -Manakibul Imamil Azam, Sadr al-Imma Makki 2/143, Imam Ibn Majah Awr Ilme Hadith 2/40