Surah Al-Baqarah (The Cow), Verse 104

یٰۤاَیُّهَا الَّذِیْنَ اٰمَنُوْا لَا تَقُوْلُوْا رَاعِنَا وَقُوْلُوا انْظُرْنَا وَاسْمَعُوْا وَلِلْكٰفِرِیْنَ عَذَابٌ اَلِیْمٌ ۟

Yaaa ayyuhal lazeena aamanoo laa taqooloo raa'inaa wa qoolun zurnaa wasma'oo; wa lilkaafireena 'azaabun aleem

“O ye of Faith! Say not (to the Messenger) words of ambiguous import, but words of respect; and hearken (to him): To those without Faith is a grievous punishment.”

Quran 2:104 (Yusuf Ali Translation)