Surah Al-Nahl (The Bees), Verse 106

مَنْ كَفَرَ بِاللّٰهِ مِنْ بَعْدِ اِیْمَانِهٖۤ اِلَّا مَنْ اُكْرِهَ وَقَلْبُهٗ مُطْمَىِٕنٌّۢ بِالْاِیْمَانِ وَلٰكِنْ مَّنْ شَرَحَ بِالْكُفْرِ صَدْرًا فَعَلَیْهِمْ غَضَبٌ مِّنَ اللّٰهِ وَلَهُمْ عَذَابٌ عَظِیْمٌ ۟

man kafara billaahi mim ba'di eemaanihee illaa man ukriha wa qalbuhoo mutmma'innum bil eemaani wa laakim man sharaha bilkufri sadran fa'alaihim ghadabum minal laahi wa lahum 'azaabun 'azeem

“Any one who, after accepting faith in Allah, utters Unbelief,- except under compulsion, his heart remaining firm in Faith - but such as open their breast to Unbelief, on them is Wrath from Allah, and theirs will be a dreadful Penalty.”

Quran 16:106 (Yusuf Ali Translation)