Quran 26:188 from Surah Ash-Shu'araa on Divine Marvels.
قَالَ رَبِّيٓ أَعۡلَمُ بِمَا تَعۡمَلُونَ
English translation: He said My Lord knows best of what you do
Transliteration: qala rabbi a'lamu bima ta'maluna