Narrated Abu Bakhtari At-Tai:
I asked Ibn 'Abbas about Salam for (the fruits of) date-palms. He replied "The Prophet forbade the sale a dates on the trees till they became fit for eating and could be weighed." A man asked what to be weighed (as the dates were still on the trees). Another man sitting Abu Al-Bakhtari: I heard Ibn Abbas (saying) that the Prophet forbade ... etc. as above.