The Messenger of Allah ﷺ forbade the sale of date palms until their fruit becomes fit to eat.
أخبرنا محمد بن عبد الأعلى قال حدثنا خالد قال حدثنا هشام عن أبي الزبير
نهى رسول الله ﷺ عن بيع النخل حتى يطعم
[Sahih] Ahmad reported it: 3/357, 372, from the hadith of Hisham Dastawai with this chain, and it is in Kubra, no. 6116. It has corroborating narrations in Bukhari, no. 187, 2189, and Muslim, no. 1536/53, and others.