The Messenger of Allah (ﷺ) said, "Whosoever possesses these four characteristics is a sheer hypocrite; and anyone who possesses one of them possesses a characteristic of hypocrisy till he gives it up. These are: when he is entrusted with something, he proves dishonest; when he speaks, he tells a lie; when he makes a covenant, he proves treacherous; and when he quarrels, he behaves in very imprudent, evil, insulting manner."

[Al-Bukhari and Muslim].