Mufazzal b. Umar said: I asked Imam Jafar b. Muhammad Sadiq (a.s.) – What is meant by Ibrahim was tried by Allah in the following words of Allah – ‘And when His Lord tried Ibrahim with certain words…(Surah Baqarah (2): 124)
Imam (a.s.) replied – This refers to the sayings which Allah heard from Adam (a.s.) and accepted Adam’s (a.s.) repentance. Adam beseeched Allah through Muhammad (s.a.w.a.), Ali (a.s.), Fatima (s.a.), Hasan (a.s.) and Husain (a.s.) to accept his (a.s.) repentance and Allah accepted it as He is the One who accepts repentance and the All-Merciful.
I asked the Imam (a.s.) – O Son of Allah’s Prophet! What is Allah’s intention in saying, ‘…he fulfilled them…’ (Surah Baqarah (2): 124).
Imam (a.s.) replied – This implies that Allah completed the names of the Imams up until the twelfth Imam nine of whom are from the progeny of Husain (a.s.).
Al-Khesaal chap 5 trad 85