Kaafir (kafir) in Arabic is derived from the root verb 'ka fa ra', meaning "he hid" a thing. As a pre-Islamic term (before Islam was established), kafir described the job of farmers who planted seeds in the ground, covering them with soil. The word implies a covering - thus, a covering of truth.
All too often the Muslim will throw around the term 'kaafir' as an insult from personal dislike, or to disapprove of the foreign "unislamic" group or to shun another Muslim from the community. The word is heavy, much like its meaning. A "true" kaafir who knowingly rejects acknowledgement in One God is only worthy of the consequence, be it Hell, or forgiveness, if God wills it on Judgement Day. Therefore no average Muslim, including myself, has the right or freedom to directly call another person a kaafir, even on the occasion that all signs indicate so.
Refer to the words 'Al Kuffara' in the Qur'an, 57:20.
And now, for the Shari`ah perspective on what kaafir means and who may use it:
- "Takfir (declaring apostasy) is not an easy affair. Just like any ruling it has certain conditions that, if not present, will prevent the ruling, in this case disbelief, from occurring." - Some conditions on calling someone a Kafir
- Brief etymology and social pressure behind the word 'kafir' on Wikipedia
- Prophet Muhammad ﷺ said, "Whoever says to his brother: 'O disbeliever (kafir),' it becomes true of one of the two." Narrated in al-Bukhari and Muslim.
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