It was narrated from 'Abdullah bin 'Umar that he said:
"Zaid bin Thabit told me that the Messenger of Allah (ﷺ) gave a concession regarding the sale of the estimated harvest of 'Araya return for dried dates." (Sahih) Yahya (one of the narrators) said: "The 'Araya is when a man purchases dates on the trees for food that his family has that is ripe, by estimating them (the dates)."
English reference: Vol. 3, Book 12, Hadith 2269
Arabic reference: Book 12, Hadith 2355