I have an Assignment that I have to Do on Economy in Madinah

It would be helpful if you refer to the Ahadith regarding trade.

This is in tafsir ibn kathir. The reason for surah Mutaffifeen [the Defrauders/cheaters etc.]

Increasing and decreasing in the Measure and Weight will be a Cause for Regret and Loss



An-Nasa'i and Ibn Majah both recorded from Ibn `Abbas that he said, "When the Prophet came to Al-Madinah, the people of Al-Madinah were the most terrible people in giving measurement (i.e., they used to cheat). Thus, Allah revealed,


[وَيْلٌ لِّلْمُطَفِّفِينَ ]




(Woe to Al-Mutaffifin.) After this, they began to give good measure.'' The meaning of the word Tatfif here is to be stingy with measurement and weight, either by increasing it if it is due from the others, or decreasing it if it is a debt. Thus, Allah explains that the Mutaffifin those whom He has promised loss and destruction, whom are meant by "Woe'' are




[الَّذِينَ إِذَا اكْتَالُواْ عَلَى النَّاسِ]




(Those who, when they have to receive by measure from men,) meaning, from among the people.


[يَسْتَوْفُونَ]


(demand full measure,) meaning, they take their right by demanding full measure and extra as well.


[وَإِذَا كَالُوهُمْ أَوْ وَّزَنُوهُمْ يُخْسِرُونَ ]




(And when they have to give by measure or weight to (other) men, give less than due.) meaning, they decrease. Verily, Allah commanded that the measure and weight should be given in full. He says in another Ayah,



[وَأَوْفُوا الْكَيْلَ إِذا كِلْتُمْ وَزِنُواْ بِالقِسْطَاسِ الْمُسْتَقِيمِ ذَلِكَ خَيْرٌ وَأَحْسَنُ تَأْوِيلاً

]
(And give full measure when you measure, and weigh with a balance that is straight. That is good and better in the end.) (17:35) Allah also says,


[وَأَوْفُواْ الْكَيْلَ وَالْمِيزَانَ بِالْقِسْطِ لاَ نُكَلِّفُ نَفْسًا إِلاَّ وُسْعَهَا]




(And give full measure and full weight with justice. We burden not any person, but with that which he can bear.) (6:152) and He says,


[وَأَقِيمُواْ الْوَزْنَ بِالْقِسْطِ وَلاَ تُخْسِرُواْ الْمِيزَانَ ]




(And observe the weight with equity and do not make the balance deficient.) (55:9) Allah destroyed the people of Shu`ayb and wiped them out because of their cheating in weights and measurements. ning, they take their right by demanding full measure and extra as well.


[وَإِذَا كَالُوهُمْ أَوْ وَّزَنُوهُمْ يُخْسِرُونَ ]


(And when they have to give by measure or weight to (other) men, give less than due.) meaning, they decrease. Verily, Allah commanded that the measure and weight should be given in full. He says in another Ayah,


[وَأَوْفُوا الْكَيْلَ إِذا كِلْتُمْ وَزِنُواْ بِالقِسْطَاسِ الْمُسْتَقِيمِ ذَلِكَ خَيْرٌ وَأَحْسَنُ تَأْوِيلاً ]


(And give full measure when you measure, and weigh with a balance that is straight. That is good and better in the end.) (17:35) Allah also says,


[وَأَوْفُواْ الْكَيْلَ وَالْمِيزَانَ بِالْقِسْطِ لاَ نُكَلِّفُ نَفْسًا إِلاَّ وُسْعَهَا]


(And give full measure and full weight with justice. We burden not any person, but with that which he can bear.) (6:152) and He says,


[وَأَقِيمُواْ الْوَزْنَ بِالْقِسْطِ وَلاَ تُخْسِرُواْ الْمِيزَانَ ]


(And observe the weight with equity and do not make the balance deficient.) (55:9) Allah destroyed the people of Shu`ayb and wiped them out because of their cheating in weights and measurements. be able to bare. Imam Malik reported from Nafi` who reported from Ibn `Umar that the Prophet said,


«يَوْمَ يَقُومُ النَّاسُ لِرَبِّ الْعَالَمِينَ، حَتْى يَغِيبَ أَحَدُهُمْ فِي رَشْحِهِ إِلَى أَنْصَافِ أُذُنَيْه»


(This will be the Day that mankind will stand before the Lord of all that exists, until one of them will sink up to the middle of his ears in sweat.) Al-Bukhari recorded this Hadith from Malik and `Abdullah bin `Awn, both of whom reported it from Nafi`. Muslim also recorded it from two routes. Another Hadith: Hadith;uA ? give less than due.) meaning, they decrease. Verily, Allah commanded that the measure and weight should be given in full. He says in another Ayah,


[وَأَوْفُوا الْكَيْلَ إِذا كِلْتُمْ وَزِنُواْ بِالقِسْطَاسِ الْمُسْتَقِيمِ ذَلِكَ خَيْرٌ وَأَحْسَنُ تَأْوِيلاً ]


(And give full measure when you measure, and weigh with a balance that is straight. That is good and better in the end.) (17:35) Allah also says,


[وَأَوْفُواْ الْكَيْلَ وَالْمِيزَانَ بِالْقِسْطِ لاَ نُكَلِّفُ نَفْسًا إِلاَّ وُسْعَهَا]


(And give full measure and full weight with justice. We burden not any person, but with that which he can bear.) (6:152) and He says,




[وَأَقِيمُواْ الْوَزْنَ بِالْقِسْطِ وَلاَ تُخْسِرُواْ الْمِيزَانَ

]


(And observe the weight with equity and do not make the balance deficient.) (55:9) Allah destroyed the people of Shu`ayb and wiped them out because of their cheating in weights and measurements.


http://tafsir.com/default.asp?sid=83&tid=57453