Thus, the Prophet’s supplication—peace and blessings be upon him—that Allah thoroughly cleanse them is like his supplication that He purify them, make them good, make them God-fearing, and the like. It is well known that anyone whose state ultimately becomes firmly established upon this is included herein. The purity for which he prayed on their behalf cannot be greater than what he prayed for himself.

He said:

“O Allah, purify me of my sins (1) with snow, hail, and cold water.”

Anyone whose sin comes to be forgiven or expiated has thereby been thoroughly purified from it by Allah. Yet one who dies (2) stained by his sins was not purified of them during his lifetime. Part of completing their purification may also be to protect them from charitable alms, which are the impurities of the people.

When the Prophet—peace and blessings be upon him—offers a supplication, Allah answers him in accordance with the recipient’s receptivity. Thus, when he seeks forgiveness for the believing men and women (3), it does not follow that no sinful believer can exist. For if that were the case, no believer would ever be punished, either in this world or in the Hereafter. Rather, Allah forgives one person through repentance and another through good deeds that erase sins. He forgives one person many sins (4), whereas in another case one sin is offset by one good deed.

In short, the purification that Allah willed and for which the Prophet—peace and blessings be upon him—prayed is not infallibility, by agreement. Ahl al-Sunna hold that no one is infallible except the Prophet—peace and blessings be upon him—whereas the Shia say, “No one is infallible other than the Prophet—peace and blessings be upon him—and the Imam.” Thus, both sides agree (5) that the special infallibility possessed by the Prophet—peace and blessings be upon him—and the Imam does not extend to his wives, his daughters, or other women.