Musnad Ahmad 27:1042

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, I heard ‘Abd Rabbih ibn Sa‘id narrating from Nafi‘, from Ibn ‘Umar, that the Messenger of Allah (may Allah bless him and grant him peace) said: "Whichever man sells date palms that have been pollinated, then their fruit belongs to the first [owner]. And whichever man sells a slave who has wealth, then his wealth belongs to his first master, unless the buyer stipulates [otherwise]." Shu‘bah said: I told him the hadith of Ayyub, from Nafi‘, that he narrated [the hadith] about the date palms from the Prophet (may Allah bless him and grant him peace), and [the hadith] about the slave from ‘Umar. ‘Abd Rabbih said: "I do not know them both except from the Prophet (may Allah bless him and grant him peace)." Then he said another time: "He narrated from the Prophet (may Allah bless him and grant him peace)," and he did not doubt.