Regarding God's statement to Abraham (a.s): “Dost thou not then believe? He said: Yea! But to satisfy my own understanding.” [The Holy Quran: Baqara 2:260] Imam Reza (a.s) was asked: “Was there any doubt in his heart?” Imam Reza (a.s) replied: “No, there was certitude in his heart. But God had decided to increase his certitude.