"the Messenger of Allah forbade selling the fruit of date palms until they are fit to eat." (Using translation from Nasāʾī 4525)

نَهَى رَسُولُ اللهِ ﷺعَنْ بَيْعِ النَّخْلِ حَتَّى يَبْدُوَ صَلَاحُهُ