‘Iṣmah or ‘Isma (; literally, "protection") is the concept of incorruptible innocence, immunity from sin, or moral infallibility in Islamic theology, and which is especially prominent in Shia Islam. In Shia theology, "ismah" is characteristic of prophets, "imams", and angels. When attributed to human beings, ismah means "the ability of avoiding acts of disobedience, in spite of having the power to commit them". Along with a pure constitution, excellent qualities, firmness against opponents, and tranquility ("as-Sakinah"), ismah is a divine grace bestowed by God.