حَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا يَحْيَى، عَنْ عُبَيْدِ اللَّهِ، أَخْبَرَنِي نَافِعٌ، عَنِ ابْنِ عُمَرَ، قَالَ كَانُوا يَتَبَايَعُونَ الطَّعَامَ جُزَافًا بِأَعْلَى السُّوقِ فَنَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم أَنْ يَبِيعُوهُ حَتَّى يَنْقُلُوهُ ‏.‏

Ibn 'Umar said: They (the people) used to buy grain in the upper part of the market in the same spot without measuring or weighing it. The Messenger of Allah (PBUH) forbade them to sell it there before removing it. Translation Not Available

Book Ref: Sunan Abi Dawud Book 24 Hadith 3494
Web Ref:  Sunan Abi Dawud Book 23 Hadith 3487