Seeking intercession of the Prophet and the Ahlulbait (peace be upon them) and asking them does not require an extra proof other than what is mentioned in the Holy Book. The following verse is sufficient to prove it, when Almighty Allah said: “And if, when they had wronged themselves, they had but come unto thee and asked forgiveness of Allah, and asked forgiveness of the messenger, they would have found Allah Forgiving, Merciful” (4:64).
