Quran 44:21 from Surah Ad-Dukhaan on Divine Marvels.
وَإِن لَّمۡ تُؤۡمِنُواْ لِي فَٱعۡتَزِلُونِ
English translation: And if not you believe me then leave me alone
Transliteration: wa-in lam tu'minu li fa-i'taziluni