Without a doubt, the tranquility and rest of a person depends on his heart and his body reassures such fact while his heart finds tranquility and rest in the remembrance of Allah (SWT). Allah (SWT) says:
“Verily, in the remembrance of Allah do hearts find rest.” (Ar-Rad 13:28).
Allah, the Exalted, says:
“And keep yourself (O Muhammad (sallallaahu alayhi wa sallam)) patiently with those who call on their Rubb (i.e., your companions who remember their Rubb with glorification, praising in prayers, and other righteous deeds) morning and afternoon, seeking His Face; and let not your eyes overlook them.” (18:28)
There is a silsila of sufiya based in Pakistan. They recite the verse o those who believe remember Allah and make zikr e kaseer ‘ (surah noor ). And the ayat ‘ And remember ( O prophet ) your lord in your nafs , with humility and fear , and without raising your voice ; remember Him in the evening and morning and do not become those who are negligent ‘ ( 8:205 ) .