Fiqh-us-Sunnah Volume 4, Funerals and Dhikr, Fiqh 4.101A.

The purpose of zhikr is to purify hearts and souls and awaken the human conscience. The Qur’an says, “And establish regular prayer, for prayer restrains from shameful and unjust deeds, and remembrance of Allah is the greatest thing in life, without doubt.” Qur’an 29.45 In other words, the remembrance of Allah has a greater impact in restraining one from shameful and unjust deeds than just the formal regular prayer. This is so because when a servant opens up his soul to his Lord, extolling His praise, Allah strengthens him with His light, increasing thereby his faith and conviction, and reassuring his mind and heart. This refers to “those who believe, and whose hearts find satisfaction in the remembrance of Allah, for without doubt in the remembrance of Allah do hearts find satisfaction.” Qur’an 13.28

And when hearts are satisfied with the Truth, they turn to the highest ideals without being deflected by impulses of desire or lust. This underscores the importance of zhikr in man’s life. Obviously it would be unreasonable to expect these results just by uttering certain words, for words of the tongue unsupported by a willing heart are of no consequence. Allah Himself has taught us the manner in which a person should remember Him, saying, “And do bring your Lord to remembrance in your very soul, with humility and in reverence, without loudness in words, in the mornings and evening, and be not of those who are unheedful.” Qur’an 7.205

This verse indicates that doing zhikr in silence and without raising one’s voice is better. Once during a journey the Prophet, peace be upon him, heard a group of Muslims supplicating aloud. Thereupon the Prophet, peace be upon him, said, “Give yourselves a respite, you are not calling upon someone deaf or absent. Surely He Whom you are calling upon is near you and He listens to all. He is nearer to you than the neck of your mount.” This hadith underlines the love and awe a person should feel while engaged in zhikr.

A part of this etiquette is the requirement that a person wishing to do zhikr be clean in body and dress, and smell sweet and fragrant. This will give him a fresh zeal and he will feel invigorated. One should face the qiblah during zhikr, for the best assemblies are those that face the Ka’bah.