Ar-Ra'd 13:28

Allatheena amanoo watatma-innuquloobuhum bithikri Allahi ala bithikriAllahi tatma-innu alquloob

Those who have believed and whose hearts are assured by the remembrance of Allāh. Unquestionably, by the remembrance of Allāh hearts are assured."

the ones who believe and their hearts are peaceful with the remembrance of Allah. Listen, the hearts find peace only in the remembrance of Allah.”