Quran 26:181 from Surah Ash-Shu'araa on Divine Marvels.
۞أَوۡفُواْ ٱلۡكَيۡلَ وَلَا تَكُونُواْ مِنَ ٱلۡمُخۡسِرِينَ
English translation: Give full measure and (do) not be of those who cause loss
Transliteration: awfu al-kayla wala takunu mina al-mukh'sirina