The doctrine of Badā’, as a specific attribute of Shiite beliefs, has constantly been the subject of derision and criticism by Shia opponents. They have accused the Shiites of attributing ignorance and remorse to God and, for that reason, have taunted them as such. In response, Shiite scholars have always defended the doctrine of Badā’ and tried, based on their own thought systems, to clarify the true nature of Badā’ and to provide an accurate account of its relationship with the divine attributes. Ayatollah Seyyed Muhammad Kazem Assar is among the recent great figures who have dealt with the doctrine of Badā’ in detail. He has developed an independent treatise on this subject with a philosophical-mystical approach. Ayatollah Assar’s initiatives in explaining the truth of Badā’, especially his mystical view of it, are unique. Using Sadra’s philosophical and mystical principles, he has managed to provide a novel and new explanation of the truth of Badā’, its relationship with the knowledge and will of God and divine destiny, and the way it is expounded through the knowledge and narratives of the Ma’suumin (P.B.U.T.). Adopting his viewpoint, the present paper is an attempt to explain the truth of Badā’ and to analyze its relationship with Knowledge, will and divine destiny, and the knowledge and infallibility of the Ma’suumin (P.B.U.T.).