Quran 51:51 from Surah Adh-Dhaariyat on Divine Marvels.
وَلَا تَجۡعَلُواْ مَعَ ٱللَّهِ إِلَٰهًا ءَاخَرَۖ إِنِّي لَكُم مِّنۡهُ نَذِيرٞ مُّبِينٞ
English translation: And (do) not make with Allah god another Indeed I am to you from Him a warner clear
Transliteration: wala taj'alu ma'a al-lahi ilahan akhara inni lakum min'hu nadhirun mubinun