Hadith 513830
Chapter 31: Business Transactions - كتاب البيوع
قَالَ مَالِكٌ عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم نَهَى عَنِ النَّجْشِ .
Malik said, from Nafi from Abdullah ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, forbade najsh. Malik said, "Najsh is to offer a man more than the worth of his goods when you do not mean to buy them and someone else follows you in bidding."
Reference Muwatta Malik 513830
USC-MSA web (English) reference : Book 31, Hadith 98