It was narrated from Nafi' from Ibn 'Umar that the Prophet (ﷺ) said:
"Whoever sells a palm tree and sells a slave." Mentioning both of them together.[1] (FR)
English reference (FR): Vol. 3, Book 12, Hadith 2212 (FR)
Arabic reference (FR): Book 12, Hadith 2297 (FR)