ٱلَّذِينَ ءَامَنُوا۟ وَتَطْمَئِنُّ قُلُوبُهُم بِذِكْرِ ٱللَّهِ ۗ أَلَا بِذِكْرِ ٱللَّهِ تَطْمَئِنُّ ٱلْقُلُوبُ
Allazeena aamanoo wa tatma'innu quloobuhum bizikril laah; alaa bizikril laahi tatma'innul quloob
Onlar inanmışlar, kalbleri Allah'ı anmakla huzura kavuşmuştur. Dikkat edin, kalbler ancak Allah'ı anmakla huzura kavuşur.
those who believe, and whose hearts find peace in the remembrance of God — truly, in the remembrance of God hearts find peace.
The verse answers a demand for a miracle made two lines earlier, and what it offers is an interior sign: the heart coming to rest. Ṭumaʾnīna is the settling of something after motion, used of ground that levels out and of a person who stops casting about. The second clause repeats the first with the words reordered and the possessive dropped, so hearts in general take the place of theirs.