Hadith 1565
'Abdullah bin 'Amr bin Al-'As (May Allah be pleased with them) reported:
وعن عبد الله بن عمرو بن العاص رضي الله عنهما قال: قال رسول الله صلى الله عليه وسلم : "المسلم من سلم المسلمون من لسانه ويده، والمهاجر من هجر ما نهى الله عنه" ((متفق عليه)).
The Messenger of Allah (ﷺ) said, "A (true) Muslim is one from whose tongue and hand the Muslims are safe; and a Muhajir (Emigrant) is he who leaves the deeds which Allah has prohibited." [Al-Bukhari and Muslim].
In plain words
A true Muslim is measured by the safety others feel around him: people are protected from his tongue and his hand. Faith shows in how harmless and trustworthy you are to those nearby.
Reference : Riyad as-Salihin 1565 In-book reference : Book 17, Hadith 55