The owner of the dates came to the Messenger of Allah ﷺ with a date, and the Messenger of Allah did not recognize this type, so he asked, "Where did you get this from?"He replied, "We bought one saa of these dates with two saa of our own dates."The Messenger of Allah ﷺ said, "You have committed riba."
حدثنا معتمر عن أبيه قال أنبأني أبو نضرة
أن صاحب التمر أتى رسول الله ﷺ بتمرة فأنكرها فقال أنى لك هذا قال اشترينا بصاعين من تمرنا صاعا فقال رسول الله ﷺ أربيتم
Its isnad is sahih. Mutamir bin Sulayman bin Tarkhan Taymi is trustworthy, as is his father, and the hadith has already appeared at 10934.