Surah Al-A'raf (The Heights), Verse 2

كِتٰبٌ اُنْزِلَ اِلَیْكَ فَلَا یَكُنْ فِیْ صَدْرِكَ حَرَجٌ مِّنْهُ لِتُنْذِرَ بِهٖ وَذِكْرٰی لِلْمُؤْمِنِیْنَ ۟

Kitaabun unzila ilaika falaa yakun fee sadrika harajum minhu litunzira bihee wa zikraa lilmu'mineen

“A Book revealed unto thee,- So let thy heart be oppressed no more by any difficulty on that account,- that with it thou mightest warn (the erring) and teach the Believers).”

Quran 7:2 (Yusuf Ali Translation)