Chapter on Sales
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 2|Chapter 11
وَ رُوِيَ عَنْ عَبْدِ اَلْمَلِكِ بْنِ عَمْرٍو قَالَ: قُلْتُ لِأَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ أَشْتَرِي مِائَةَ رَاوِيَةٍ مِنْ زَيْتٍ وَ أَعْتَرِضُ رَاوِيَةً أَوِ اِثْنَتَيْنِ وَ أَتَّزِنُهُمَا ثُمَّ آخُذُ سَائِرَهُ عَلَى قَدْرِ ذَلِكَ فَقَالَ "لاَ بَأْسَ".
It is narrated from Abdul-Malik bin Amr who said: I said to Abu Abdillah عليه السلام, "I purchase one hundred containers of oil, and I inspect one or two containers and weigh them, then take the rest based on that measurement." Imam عليه السلام said: "There is no harm."
- Ṣaḥīḥ al-Faqīh, p. 228