Chapter on Sales
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 2|Chapter 11
وَ رَوَى اِبْنُ مُسْكَانَ عَنِ اَلْحَلَبِيِّ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ أَنَّهُ قَالَ: فِي رَجُلٍ اِشْتَرَى مِنْ رَجُلٍ طَعَاماً عِدْلاً بِكَيْلٍ مَعْلُومٍ وَ إِنَّ صَاحِبَهُ قَالَ لِلْمُشْتَرِي اِبْتَعْ مِنِّي هَذَا اَلْعِدْلَ اَلْآخَرَ بِغَيْرِ كَيْلٍ فَإِنَّ فِيهِ مَا فِي اَلْآخَرِ اَلَّذِي اِبْتَعْتَهُ قَالَ "لاَ يَصْلُحُ إِلاَّ بِكَيْلٍ" قَالَ وَ "مَا كَانَ مِنْ طَعَامٍ سَمَّيْتَ فِيهِ كَيْلاً فَإِنَّهُ لاَ يَصْلُحُ مُجَازَفَةً هَذَا مِمَّا يُكْرَهُ مِنْ بَيْعِ اَلطَّعَامِ".
Ibn Muskan narrated from Al-Halabi, from Abu Abdillah عليه السلام: Regarding a man who purchased a measured amount of food from another man, and then the seller said to the buyer, "Buy this other sack without measuring it, for it contains the same amount as the one you already purchased." Imam عليه السلام said: "This is not permissible unless it is measured." Imam عليه السلام further said: "Any food for which a specific measurement has been stipulated cannot be sold without measuring it. Such sales, based on estimation, are disapproved in the case of food."
- Ṣaḥīḥ al-Faqīh, p. 221