Surah Al-Fat'h (The Victory), Verse 26

اِذْ جَعَلَ الَّذِیْنَ كَفَرُوْا فِیْ قُلُوْبِهِمُ الْحَمِیَّةَ حَمِیَّةَ الْجَاهِلِیَّةِ فَاَنْزَلَ اللّٰهُ سَكِیْنَتَهٗ عَلٰی رَسُوْلِهٖ وَعَلَی الْمُؤْمِنِیْنَ وَاَلْزَمَهُمْ كَلِمَةَ التَّقْوٰی وَكَانُوْۤا اَحَقَّ بِهَا وَاَهْلَهَا وَكَانَ اللّٰهُ بِكُلِّ شَیْءٍ عَلِیْمًا 

Iz ja'alal lazeena kafaroo fee quloobihimul hamiyyata hamiyyatal jaahiliyyati fa anzalal laahu sakeenatahoo 'alaa Rasoolihee wa 'alal mu mineena wa alzamahum kalimatat taqwaa wa kaanooo ahaqqa bihaa wa ahlahaa; wa kaanal laahu bikulli shai'in Aleema

“While the Unbelievers got up in their hearts heat and cant - the heat and cant of ignorance,- Allah sent down His Tranquillity to his Messenger and to the Believers, and made them stick close to the command of self-restraint; and well were they entitled to it and worthy of it. And Allah has full knowledge of all things.”

Quran 48:26 (Yusuf Ali Translation)