It is narrated from Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever sells a date-palm tree after it has been pollinated, its fruit belongs to the seller, except if the buyer stipulates (that he will take the fruit as well)."
Hadith Referenceمسند الإمام الشافعي / كتاب البيوع / 1368
Hadith Takhrijاخرجه البخاري، البيوع، باب من باع نخلا قد ابرت او ارضا مز روعة او باجارة (2204) - ومسلم، البيوع، باب من باع نخلا عليها تمر (1543)۔