Sunan an-Nasa'i · Hadith 4505
أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم نَهَى عَنِ النَّجْشِ .
It was narrated from Ibn 'Umar that:the Prophet forbade artificially inflating prices
Sahih · Abu GhuddahSahih · Al-AlbaniSahih - Agreed Upon · Zubair Ali Zai