The word(s) "اطمأن" appears in 3 verse(s) in Quran.

(1) فَإِذَا قَضَيْتُمُ الصَّلَاةَ فَاذْكُرُوا اللَّهَ قِيَامًا وَقُعُودًا وَعَلَىٰ جُنُوبِكُمْ ۚ فَإِذَا اطْمَأْنَنتُمْ فَأَقِيمُوا الصَّلَاةَ ۚ إِنَّ الصَّلَاةَ كَانَتْ عَلَى الْمُؤْمِنِينَ كِتَابًا مَّوْقُوتًا

(سورة النساء, An-Nisaa, Chapter #4, Verse #103)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) إِنَّ الَّذِينَ لَا يَرْجُونَ لِقَاءَنَا وَرَضُوا بِالْحَيَاةِ الدُّنْيَا وَاطْمَأَنُّوا بِهَا وَالَّذِينَ هُمْ عَنْ آيَاتِنَا غَافِلُونَ

(سورة يونس, Yunus, Chapter #10, Verse #7)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(3) وَمِنَ النَّاسِ مَن يَعْبُدُ اللَّهَ عَلَىٰ حَرْفٍ ۖ فَإِنْ أَصَابَهُ خَيْرٌ اطْمَأَنَّ بِهِ ۖ وَإِنْ أَصَابَتْهُ فِتْنَةٌ انقَلَبَ عَلَىٰ وَجْهِهِ خَسِرَ الدُّنْيَا وَالْآخِرَةَ ۚ ذَ‌ٰلِكَ هُوَ الْخُسْرَانُ الْمُبِينُ

(سورة الحج, Al-Hajj, Chapter #22, Verse #11)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)