وَأَوْفُوا الْكَيْلَ إِذَا كِلْتُمْ وَزِنُوا بِالْقِسْطَاسِ الْمُسْتَقِيمِ ۚ ذَٰلِكَ خَيْرٌ وَأَحْسَنُ تَأْوِيلًا
Give full measure when ye measure, and weigh with a balance that is straight: that is the most fitting and the most advantageous in the final determination. Surah Bani-Israel Ayat 35