The Quran root ك ف ر k-f-r

إِنَّ الَّذِينَ كَفَرُوا سَوَاءٌ عَلَيْهِمْ أَأَنذَرْتَهُمْ أَمْ لَمْ تُنذِرْهُمْ لَا يُؤْمِنُونَ ٦

كَفَرُوا kafarū · disbelieve[d]

Indeed, those who disbelieve - it is all the same for them whether you warn them or do not warn them - they will not believe. (Surah Al-Baqarah, 2:6)

إِنَّ اللَّهَ لَا يَسْتَحْيِي أَن يَضْرِبَ مَثَلًا مَّا بَعُوضَةً فَمَا فَوْقَهَا فَأَمَّا الَّذِينَ آمَنُوا فَيَعْلَمُونَ أَنَّهُ الْحَقُّ مِن رَّبِّهِمْ وَأَمَّا الَّذِينَ كَفَرُوا فَيَقُولُونَ مَاذَا أَرَادَ اللَّهُ بِهَٰذَا مَثَلًا يُضِلُّ بِهِ كَثِيرًا وَيَهْدِي بِهِ كَثِيرًا وَمَا يُضِلُّ بِهِ إِلَّا الْفَاسِقِينَ ٢٦

كَفَرُوا kafarū · disbelieved

Indeed, Allāh is not timid to present an example - that of a mosquito or what is smaller than it. And those who have believed know that it is the truth from their Lord. But as for those who disbelieve, they say, "What did Allāh intend by this as an example?" He misleads many thereby and guides many thereby. And He misleads not except the defiantly disobedient, (Surah Al-Baqarah, 2:26)

أَوْ كَصَيِّبٍ مِّنَ السَّمَاءِ فِيهِ ظُلُمَاتٌ وَرَعْدٌ وَبَرْقٌ يَجْعَلُونَ أَصَابِعَهُمْ فِي آذَانِهِم مِّنَ الصَّوَاعِقِ حَذَرَ الْمَوْتِ وَاللَّهُ مُحِيطٌ بِالْكَافِرِينَ ١٩

بِالْكَافِرِينَ bil-kāfirīna · the disbelievers

Or [it is] like a rainstorm from the sky within which is darkness, thunder and lightning. They put their fingers in their ears against the thunderclaps in dread of death. But Allāh is encompassing of the disbelievers. (Surah Al-Baqarah, 2:19)

وَقَالُوا قُلُوبُنَا غُلْفٌ بَل لَّعَنَهُمُ اللَّهُ بِكُفْرِهِمْ فَقَلِيلًا مَّا يُؤْمِنُونَ ٨٨

بِكُفْرِهِمْ bikuf'rihim · for their disbelief

And they said, "Our hearts are wrapped." But, [in fact], Allāh has cursed them for their disbelief, so little is it that they believe. (Surah Al-Baqarah, 2:88)

إِن تُبْدُوا الصَّدَقَاتِ فَنِعِمَّا هِيَ وَإِن تُخْفُوهَا وَتُؤْتُوهَا الْفُقَرَاءَ فَهُوَ خَيْرٌ لَّكُمْ وَيُكَفِّرُ عَنكُم مِّن سَيِّئَاتِكُمْ وَاللَّهُ بِمَا تَعْمَلُونَ خَبِيرٌ ٢٧١

وَيُكَفِّرُ wayukaffiru · And He will remove

If you disclose your charitable expenditures, they are good; but if you conceal them and give them to the poor, it is better for you, and He will remove from you some of your misdeeds [thereby]. And Allāh, of what you do, is [fully] Aware. (Surah Al-Baqarah, 2:271)

وَلَئِنْ أَذَقْنَا الْإِنسَانَ مِنَّا رَحْمَةً ثُمَّ نَزَعْنَاهَا مِنْهُ إِنَّهُ لَيَئُوسٌ كَفُورٌ ٩

كَفُورٌ kafūrun · (and) ungrateful

And if We give man a taste of mercy from Us and then We withdraw it from him, indeed, he is despairing and ungrateful. (Surah Hud, 11:9)