To Al-Raghib al-Isfahani and Murtada al-Zabidi, Ismah is God's preservation of the infallibles, accomplished in stages. The first stage is to bestow on infallibles a robust constitution, followed by excellent qualities, then a firm will against opponents and enemies, followed by the sending of tranquility ("as-Sakina") down upon them, and by the preparation of their hearts and minds to accept truth. The final stage is endowing the infallibles with "the ability to avoid acts of disobedience in spite of having the power to disobey".