It should be noted that in some of the Traditions which have reached us from the Sunnis, the names of the twelve Imams have clearly appeared and their names specified!

Shaykh Sulayman Qanduzi, a famous Sunni scholar, in the book, Yanabi’ al-Muwarjdah says, “A Jewish man named Na’thal, went to the Prophet and among the questions he asked who would succeed him. The Prophet said, specifying them, “After me, Ali ibn Abi Tahib and then my two Sons, Hasan and Husayn and after Husayn, nine Imams will follow from his children.”

The Jewish man said, ‘Name them.’

The Prophet said, ‘When Husayn leaves this world, his son, Ali, and after him, his child Muhammad and after Muhammad his son Ja’far and after Ja’far, his son Musa and after Musa, his son Ali and after Ali, Muhammad. After Muhammad, his child, Ali and after Ali, Hasan and after Hasan, his child Muhammad al-Mahdi. These are the twelve Imams.” (Yanabi ‘al-Muwadat, p. 431).

In that same book another Tradition is quoted from Kitab Manaqib with their titles and it indicates that Imam Mahdi is in occultation and then he will arise and replace the oppression and tyranny which exists upon the earth with justice.” (Yanabi al-Muwadat, p.442).

Of course, there are many Traditions relating to this in Sunni sources. (Note this with care).