Sayyiduna Zayd bin Thabit (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) "granted a concession in the 'ariyyah sale for (selling) the fruit on the tree by estimation."
(b) Yahya bin Sa'id (may Allah have mercy on him) said: 'Ariyyah is that a man buys the fruit of date palms for his family to eat, in exchange for dried dates by estimation.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10661