✅Answer: Please pay attention to the following narrations:

1 عَنْ مُحَمَّدِ بْنِ إِسْمَاعِيلَ عَنْ حَنَانٍ قَالَ: كُنْتُ جَالِساً عِنْدَ أَبِي عَبْدِ اللَّهِ فَقَالَ لَهُ مَعْمَرٌ الزَّيَّاتُ إِنَّا نَشْتَرِي الزَّيْتَ فِي زِقَاقِهِ وَ يُحْسَبُ لَنَا فِيهِ نُقْصَانٌ لِمَكَانِ الزِّقَاقِ فَقَالَ إِنْ كَانَ يَزِيدُ وَ يَنْقُصُ فَلَا بَأْسَ وَ إِنْ كَانَ يَزِيدُ وَ لَا يَنْقُصُ فَلَا تَقْرَبْهُ.

📚 Al-Kafi, vol. 5, p. 183

Hanan said: I was sitting with Imam Sadiq, peace be upon him; then Ma'mar the oil seller said to the Imam: We buy olive oil in its skins, and because of its skins, a smaller amount is calculated for us! The Imam said: If (its net weight) sometimes increases and sometimes decreases, there is no problem, and if (its net weight) always increases and does not decrease, do not approach it!

2 عَبْدُ اللَّهِ بْنُ جَعْفَرٍ فِي قُرْبِ الْإِسْنَادِ عَنْ عَبْدِ اللَّهِ بْنِ الْحَسَنِ عَنْ جَدِّهِ عَلِيِّ بْنِ جَعْفَرٍ عَنْ أَخِيهِ مُوسَى بْنِ جَعْفَرٍ قَالَ: سَأَلْتُهُ عَنِ الرَّجُلِ يَشْتَرِي الْمَتَاعَ وَزْناً فِي النَّاسِيَةِ وَ الْجُوَالِقِ فَيَقُولُ ادْفَعْ لِلنَّاسِيَةِ رِطْلًا أَوْ أَقَلَّ أَوْ أَكْثَرَ مِنْ ذَلِكَ أَ يَحِلُّ ذَلِكَ الْبَيْعُ قَالَ إِذَا لَمْ يُعْلَمْ وَزْنُ النَّاسِيَةِ وَ الْجُوَالِقِ فَلَا بَأْسَ إِذَا تَرَاضَيَا.

📚 Qurb Al-Isnad, p. 113

Ali ibn Ja'far said: I asked Musa ibn Ja'far, peace be upon him, about a person who buys a commodity by weight in a container and sack, so he says: Deduct one rattl or less or more for its container. Is this transaction permissible? The Imam said: If the weight of the container and sack is not known, there is no problem with the agreement and consent of the two parties!

3 عَنْ عَلِيِّ بْنِ أَبِي حَمْزَةَ قَالَ: سَمِعْتُ مَعْمَرَ الزَّيَّاتِ يَسْأَلُ أَبَا عَبْدِ اللَّهِ فَقَالَ جُعِلْتُ فِدَاكَ إِنِّي رَجُلٌ أَبِيعُ الزَّيْتَ إِلَى أَنْ قَالَ قُلْتُ فَإِنَّهُ يُطْرَحُ لِظُرُوفِ السَّمْنِ وَ الزَّيْتِ لِكُلِّ ظَرْفٍ كَذَا وَ كَذَا رِطْلًا فَرُبَّمَا زَادَ وَ رُبَّمَا نَقَصَ فَقَالَ إِذَا كَانَ ذَلِكَ عَنْ تَرَاضٍ مِنْكُمْ فَلَا بَأْسَ.

📚 Al-Tahdheeb, vol. 7, p. 128

Ali ibn Abi Hamzah said: I heard Ma'mar the oil seller asking Imam Sadiq, peace be upon him, and he said: May I be your sacrifice! I am a seller of olive oil.... until he said: I said: Indeed, for the containers of animal fat and olive oil, such and such a rattl is deducted for each container, and sometimes it is more and sometimes it is less!

The Imam said: If it is with the agreement and consent of the two parties, there is no problem!

✅ Based on the above narrations, goods that are inside containers such as sacks, drums, cartons, boxes, and the like and are sold by weight, and the weight of their containers is not fixed and known, a rough and average weight can be deducted from the gross weight with the consent and agreement of the two parties at the time of sale, and the net weight is transacted, on the condition that it is such that it sometimes increases and sometimes decreases.

But if its net weight after deducting the probable weight of that container is always and constantly more, it is not valid.

✅ It is clear that in a situation where the weight of the containers is exactly known, by deducting it from the gross weight, the net weight is transacted.

✅ For goods like basket fruits that are sold today with the agreement and consent and awareness of the two parties, with the container and as gross weight, no prohibition has been reported for it. But if it is to be transacted with net weight and the weight of its containers is not known, the above narrations should be taken into consideration and acted upon.

اللَّهُمَّ فَصَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ