✅ Please pay attention to the following narrations:

1 زُرارة عَنْ أَبِي جَعْفَر قَالَ: الْبَعِيرُ بِالْبَعِيرَيْنِ و الدَّابَّةُ بِالدَّابَّتَيْنِ يَداً بِيَدٍ لَيْسَ بِهِ بَأْسٌ و قَالَ لَا بَأْسَ بِالثَّوْبِ بِالثَّوْبَيْنِ يَداً بِيَدٍ و نَسِيئَةً إِذَا وَصَفْتَهُمَا

📚 Al-Faqih, Vol. 3, p. 279

Imam Baqir (prayers of Allah be upon him) said: The exchange of one camel for two camels and one animal for two animals, hand to hand (in cash), is not a problem. And he said: The exchange of one garment for two garments, hand to hand (i.e., in cash) and on credit, is not a problem, as long as you specify their characteristics!

2 عَبد الرحمن بْنِ أَبِي عَبْداللَّه قال: سَأَلْتُ أَبَا عَبْداللَّه عَنِ الْعَبْدِ بِالْعَبْدَيْنِ و الْعَبْدِ بِالْعَبْدِ وَ الدَّرَاهِمِ قَالَ لَا بَأْسَ بِالْحَيَوَانِ كُلِّهِ يَداً بِيَدٍ

📚 Al-Kafi, Vol. 5, p. 191

Abdurrahman said: I asked Imam Sadiq (prayers of Allah be upon him) about the transaction of one slave for two slaves and the transaction of one slave for one slave and a few dirhams. The Imam said: The transaction of all animals (i.e., living beings) in cash is not a problem!

3 عَلِيِّ بْنِ جَعْفَر عَنْ أَخِيهِ مُوسَى بْنِ جَعْفَرٍ قَال: سَأَلْتُهُ عَنِ الْحَيَوَانِ بِالْحَيَوَانِ بِنَسِيئَةٍ وَ زِيَادَةِ دَرَاهِمَ يَنْقُدُ الدَّرَاهِمَ وَ يُؤَخِّرُ الْحَيَوَانَ قَالَ إِذَا تَرَاضَيَا فَلَا بَأْسَ

📚 Qurb al-Isnad, 113

Ali ibn Ja'far said: I asked Musa ibn Ja'far (prayers of Allah be upon him) about an animal for an animal on credit with a few extra dirhams, which are paid in cash, and the delivery of the animal is delayed. The Imam said: If the parties agree and are satisfied with each other, there is no problem!

4 داود بْنِ الْحُصَین أَنَّهُ سَأَلَ أَبَا عَبْدِ اللَّه عَنِ الشَّاةِ بِالشَّاتَيْنِ وَ الْبَيْضَةِ بِالْبَيْضَتَيْنِ فَقَالَ لَا بَأْسَ مَا لَمْ يَكُنْ مَكِيلًا أَوْ مَوْزُوناً

📚 Al-Faqih, Vol. 3, p. 281

Dawud ibn Husayn asked Imam Sadiq (prayers of Allah be upon him) about the exchange and transaction of one sheep for two sheep and one egg for two eggs. The Imam said: As long as it is not a measured or weighed item, there is no problem!

5 الحلبیّ عَنْ أَبِي عَبْداللَّه قَالَ: لَا بَأْسَ بِمُعَاوَضَةِ الْمَتَاعِ مَا لَمْ يَكُنْ كَيْلًا وَ لَا وَزْناً

📚 Al-Faqih, Vol. 3, p. 282

Imam Sadiq (prayers of Allah be upon him) said: The exchange of goods (with another good with a difference in quantity) is not a problem as long as those goods are not measured or weighed!

6 عن زرارة عَنْ أَبِي عَبْداللَّه قَالَ: لَا يَكُونُ الرِّبَا إِلَّا فِيمَا يُكَالُ أَوْ يُوزَنُ

📚 Al-Tahdhib, Vol. 7, p. 19

Imam Sadiq (prayers of Allah be upon him) said: Usury is not found except in what is measured or weighed!

7 عَلِيِّ بْنِ إِبْرَاهِيمَ عَنْ رِجَالِهِ ذَكَرَهُ فِي حَدِيثٍ طَوِيلٍ قَالَ: وَ لَا يُنْظَرُ فِيمَا يُكَالُ أو يُوزَنُ إِلَّا إِلَى الْعَامَّةِ وَ لَا يُؤْخَذُ فِيهِ بِالْخَاصَّة

📚 Al-Kafi, Vol. 5, p. 192

Ali ibn Ibrahim narrated from his men that (the Imam, peace be upon him) said: To determine what is measured or weighed, one does not look except at the general custom and the majority, and in this matter, the practice of a specific group is not taken into account...

✅ From the above narrations and others, it is clear that if two goods or two living beings, such as ornamental fish, pigeons, clothing, and the like, are not traded by weight or measure among the majority of people, their exchange and transaction are not a problem, even with a difference in quantity.

For example, a pigeon, which is not traded by weight, has no problem being exchanged and transacted for two or more pigeons, or one pigeon can be exchanged for another pigeon and a sum of money.

Today, given that some animals such as cows, sheep, camels, and so on are traded by weight, they cannot be exchanged with a difference in quantity, even though some narrations from the time of Imam Sadiq (prayers of Allah be upon him) permitted their exchange with a difference in quantity because they were not sold by weight at that time.

For example, today you cannot exchange one large sheep for two small sheep, but you can exchange one valuable pigeon for several less valuable pigeons, or ornamental fish can be exchanged with a difference in quantity, but edible fish, due to being sold by weight, cannot be exchanged with a difference. In such cases where the exchange of two goods with a difference in quantity is considered usury, each good must be sold to the other party at its specific price. For example, if they intend to exchange one large sheep for two small sheep, he must sell that one sheep to him at a price and buy the two sheep from him separately so that it is not usury.

Exchange of animals