Musnad Ahmad 27:404

Yazid narrated to us, Hammad ibn Salamah informed us, from Ikrimah ibn Khalid al-Makhzumi, from Ibn Umar, that a man bought palm trees whose owner had already pollinated them. He disputed with him before the Prophet, peace and blessings of Allah be upon him. The Messenger of Allah, peace and blessings of Allah be upon him, judged that the fruit belongs to its owner who pollinated it, unless the buyer stipulates otherwise.