"Beware of suspicion" means such suspicion about a Muslim for which no apparent evidence is available. Similar is the case of that thought which emerges in one's mind without any logic. "Najsh" means to give higher bid in auction only to deceive others. Thus, it is a false bid which is not at all intended for purchasing the thing which is being auctioned. The instructions given to the Muslims in this Hadith are meant to secure the honour of Muslims. Since, doubt without any reason, and search for defects and weaknesses go against the security of a Muslim's honour, Islam has strictly forbidden Muslims from them. Another purpose for forbidding such things is to consolidate Muslim brotherhood. For this reason, they have been forbidden from oppression, leaving their Muslim brothers in lurch, considering others humble, and from taking pride in worldly possessions. In fact, the life, property, and honour of a Muslim have been declared unlawful for all other Muslims. Increase in a bid without any intention of buying the thing being auctioned and bargain over a bargain have also been prohibited because they also create ill-will and enmity.