(9) باب تَحْرِيمِ الظَّنِّ وَالتَّجَسُّسِ وَالتَّنَافُسِ وَالتَّنَاجُشِ وَنَحْوِهَا
Abu Huraira reported Allah's Messenger (ﷺ) as saying. Don't nurse malice against one another, don't nurse aversion against one another and don't be inquisitive about one another and don't outbid one another (with a view to raising the price) and be fellow-brothers and servants of Allah.
Reference: Sahih Muslim 2563 c
In-book reference: Book 45, Hadith 37
USC-MSA web (English) reference(deprecated numbering scheme): Book 32, Hadith 6216