Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: When I came to Madinah Munawwarah, the Prophet Muhammad (peace and blessings be upon him) was in Khaybar at that time. A man from the tribe of Banu Ghifar was leading the people in the morning prayer. In the first rak'ah, he recited Surah Maryam, and in the second rak'ah, he recited Surah Mutaffifin. Among us, there was a man who had two types of measures: one was a large measure and the other was a small one. He would give (goods) by measuring with one and receive (goods) by measuring with the other. (This thought came to my mind), so I said: That person is ruined.