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 ﷺ forbade them to sell it there before removing it. (Using translation from Abū Dāʾūd 3494)
كَانُوا يَتَبَايَعُونَ الطَّعَامَ جُزَافًا بِأَعْلَى السُّوقِ فَنَهَاهُمْ رَسُولُ اللهِ ﷺ أَنْ يَبِيعُوهُ حَتَّى يَنْقُلُوهُ