Riyad as-Salihin, Book 18, Hadith 1580 (In-Book) ⓘ
Abu Hurairah (May Allah be pleased with him) said: The Messenger of Allah said, "Do not practise Najsh (to cheat)."[Muslim].
وعنه أن رسول الله صلى الله عليه وسلم ، قال: " لا تناجشوا" ((متفق عليه)).