وَيْلٌ لِّلْمُطَفِّفِينَ ۝ الَّذِينَ إِذَا اكْتَالُوا عَلَى النَّاسِ يَسْتَوْفُونَ ۝ وَإِذَا كَالُوهُمْ أَو وَّزَنُوهُمْ يُخْسِرُونَ

These verses strongly condemn those who practice dishonesty in business dealings, specifically in weights and measures. The "mutaffifin" are those who cheat by taking full measure when receiving but giving less when selling. This represents a broader principle of fairness and justice in all transactions. The severe warning ("woe") indicates that such dishonesty is a major sin that brings divine punishment. This teaching emphasizes that Islam requires complete honesty in business dealings and that cheating others, even in small amounts, is a serious moral violation. The verses establish that economic justice and fair dealing are fundamental religious obligations, not just social conventions.