Surah Az-Zukhruf (The Ornaments of Gold), Verse 89

فَاصْفَحْ عَنْهُمْ وَقُلْ سَلٰمٌ فَسَوْفَ یَعْلَمُوْنَ 

Fasfah 'anhum wa qul salaam; fasawfa ya'lamoon

“But turn away from them, and say "Peace!" But soon shall they know!”

Quran 43:89 (Yusuf Ali Translation)