It was narrated that Abul Bakhtari at-Ta'i said:

I asked Ibn ‘Abbas (رضي الله عنه) about selling date palm trees. He said: The Messenger of Allah (ﷺ) forbade selling date palm trees until he eats from it or it is eaten from, and until (the fruit) is weighed. I said: What does weighed mean? A man who was with him said: Until it is estimated.