If it is objected, “The Messenger, may Allah bless him and grant him peace, explained faith by specifying what one believes in,” the reply is:

The Messenger mentioned what one believes in, not whom one believes. He himself must both be believed in and be believed. Belief in him, insofar as it affirms his reality, concerns something unseen to us of which we have been informed. Yet not everything unseen that we believe in must be obeyed. By contrast, the obligation to believe him entails obeying him. The Messenger must both be believed in and be believed; this distinction should therefore be understood. Moreover, obedience to him is obedience to Allah, and obedience to Allah is part of the completeness of faith in Him.

Fourth: Some people say that īmān (faith) derives linguistically from amn (security), which is the opposite of fear. Thus, āmana means “to enter a state of security.” They cite the following verse of poetry: … (1).

As for the “second premise,” the response is this: even assuming that faith is synonymous with accepting something as true, there are two answers to their assertion that this acceptance can occur only in the heart or through the tongue.

The first is to reject that assertion. Actions too are called tasdīq (confirmation), as established in the Sahīh, where the Prophet, may Allah bless him and grant him peace, said:

“The eyes commit adultery, and their adultery is looking; the ear commits adultery, and its adultery is listening; the hand commits adultery, and its adultery is grasping; the foot commits adultery, and its adultery is walking. The heart wishes for this and desires it, and the private parts confirm it or deny it.”

The linguists and various groups among the early and later generations likewise stated this. Al-Jawharī said:

“The word siddīq, formed on the same pattern as fissīq, denotes someone who constantly affirms the truth. It may also denote someone whose deeds bear out his words.”

Al-Hasan al-Basrī said:

“Faith is neither outward adornment nor wishful thinking. Rather, it is what settles firmly in the hearts and is confirmed by deeds.”

This