Tafsir Ibn Kathir -> Surah At-Taubah -> People of the Scriptures try to extinguish the Light of Islam

Allah says, the disbelieving idolators and People of the Scriptures want to,

﴿أَن يُطْفِئُواْ نُورَ اللَّهِ﴾

(extinguish the Light of Allah). They try through argument and lies to extinguish the guidance and religion of truth that the Messenger of Allah was sent with. Their example is the example of he who wants to extinguish the light of the sun or the moon by blowing at them! Indeed, such a person will never accomplish what he sought. Likewise, the light of what the Messenger was sent with will certainly shine and spread. Allah replied to the idolators' desire and hope,

﴿وَيَأْبَى اللَّهُ إِلاَّ أَن يُتِمَّ نُورَهُ وَلَوْ كَرِهَ الْكَـفِرُونَ﴾

(but Allah will not allow except that His Light should be perfected even though the disbelievers (Kafirun) hate (it)) ﴿9:32﴾. ﴿Linguistincally﴾ a Kafir is the person who covers something. For instance, night is called Kafiran ﴿covering﴾ because it covers things ﴿with darkness﴾. The farmer is called Kafiran, because he covers seeds in the ground. Allah said in an Ayah,

﴿أَعْجَبَ الْكُفَّارَ نَبَاتُهُ﴾

(thereof the growth is pleasing to the ﴿Kuffar﴾ tillers)﴿57:20﴾.