Chapter on Sales
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 2|Chapter 11
وَ سَأَلَ عَبْدُ اَلرَّحْمَنِ بْنُ أَبِي عَبْدِ اَللَّهِ أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ: فِي اَلرَّجُلِ يَشْتَرِي اَلطَّعَامَ أَشْتَرِيهِ مِنْهُ بِكَيْلِهِ وَ أُصَدِّقُهُ فَقَالَ "لاَ بَأْسَ وَ لَكِنْ لاَ تَبِعْهُ حَتَّى تَكِيلَهُ".
Abd Al-Rahman ibn Abi Abdillah asked Abu Abdillah عليه السلام about a man who buys food and then sells it back to the same seller based on the original measurement, trusting him regarding the quantity. Imam عليه السلام said: "There is no harm in this, but do not sell it until you measure it."
- Ṣaḥīḥ al-Faqīh, p. 221