If the person had any belief in the Hereafter...
If the person had any belief in the Hereafter, he would know that, even if he succeedes in fooling people, he would never be able to hide his fraud from the Lord of the worlds; he would realize that on the Day of Judgement he would have to account for whatever he has earned by defrauding and make good the loss. A butcher who was an idol-worshipper used to give more than the prescribed weight.
When people asked him the reason for this he pointed up towards the top of the wall and said, “I give more because of him.” When people looked up they saw an idol installed there. Another idol-worshipping shopkeeper was well known for his habit of casting a glance at the idol before he proceeded to weigh some goods. When Hazrat Yūsuf (a.s.) and Zulekha were alone in the room, Zulekha covered the idol with a cloth.
Hazrat Yūsuf (a.s.) asked her, “Why have you covered the idol?” She said, “I feel ashamed before it!” Hazrat Yūsuf (a.s.) said, “You feel ashamed before a lifeless idol created by men, when it has no power of understanding. How can I not feel ashamed before the Almighty Lord Who is ever present and all-seeing?” Saying this he fled from that place and saved himself from fornication.
It is a great pity that idol worshippers are ashamed to commit sins in view of their idols, which are lifeless objects, whereas Muslims have no qualms in commiting sins before Allah (S.w.T.) for Whom nothing is hidden in the heaven and the earth. Five sins and their punishments The following tradition has been recorded from the Holy Prophet (S) in the book Tafsīr Minhaj us-Sādiqīn According to this tradition there are five types of sins which bring about five types of calamities.
“When the people of a community break promises and oaths, Allah makes their enemies to reign upon them. When people order against the revealed Divine commands, poverty (certainly) is widespread. When immorality is practised openly deadly diseases certainly increase. When people short-weigh and short-measure then there is a decrease in agricultural output.
(Decrease in livelihood) and there is less rainfall.” Advice of Amir ul-Mu’minīn ‘Ali (a.s.) for the businessmen Whatever ‘Ali (a.s.) found himself free from the administrative work, he used to go to the market place and announce, “O people! Fear Allah! Weigh and measure with justice. Do not cheat people (by giving less) and do not spread corruption in the earth.” One day ‘Ali (a.s.) saw a saffron seller short-weighing.