Sahih al-Bukhari 2139

Arabic

حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ لاَ يَبِيعُ بَعْضُكُمْ عَلَى بَيْعِ أَخِيهِ ‏"‏‏.‏

Translation

Narrated `Abdullah bin `Umar:Allah's Messenger (ﷺ) said, "Do not urge somebody to return what he has already bought (i.e. in optional sale) from another seller so as to sell him your own goods

Authenticity

Sahih

Reference