(99) باب الشِّرَاءِ وَالْبَيْعِ مَعَ الْمُشْرِكِينَ وَأَهْلِ الْحَرْبِ
Narrated `Abdur-Rahman bin Abu Bakr:
We were with the Prophet (ﷺ) when a tall pagan with long matted unkempt hair came driving his sheep. The Prophet (ﷺ) asked him, "Are those sheep for sale or for gifts?" The pagan replied, "They are for sale." The Prophet (ﷺ) bought one sheep from him.
Reference: Sahih al-Bukhari 2216
In-book reference: Book 34, Hadith 163
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 34, Hadith 419