and His saying:

“He is the One who sent down tranquillity into the hearts of the believers so that they might increase in faith along with their existing faith,”

and other such verses.

If it is asked, “If this form of remembrance is not prescribed, is it disliked?” I reply: In the case of someone who is overwhelmed, it is not deemed disliked. The heart may experience states in which speech becomes difficult, even while it is filled with states of faith. A person may then be able to invoke the name alone, but not a complete expression. Such people offer what their hearts contain of faith and whatever their tongues are capable of uttering.

For people fall into four categories with regard to remembrance:

(First) Remembrance with both heart and tongue. This is what is commanded.

(Second) Remembrance with the heart alone. If this is because the tongue is unable to speak, it is good; but if the tongue is capable, it means forgoing what is better.

(Third) Remembrance with the tongue alone: keeping one’s tongue moist with the remembrance of Allah. In this connection, there is the account of one in whom the angels found no good except the movement of his tongue in remembrance of Allah. Allah Most High says:

“I am with My servant as long as he remembers Me and his lips move in remembrance of Me.”

(Fourth) Neither form of remembrance. This is the condition of those who are losers.