Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever sells palm trees after pollination, their fruit belongs to the first owner; and whoever sells a slave who has property, the property belongs to the first owner, unless the buyer stipulates (otherwise)." Shu'bah said: I told (him) the hadith of Ayyub from Nafi', in which the story of the palm trees is from the Prophet (peace and blessings be upon him) and the story of the slave is from Sayyiduna Umar (may Allah be pleased with him). Abd Rabbih said that both stories are from the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10766