Hawzah News Agency – Imam al-Sadiq peace be upon him says:

المؤمنُ مَن طابَ مَكْسبُهُ، وحَسُنتْ خَليقَتُه، وصَحَّتْ سَريرَتُهُ، وأنْفقَ الفَضلَ مِن مالِهِ، وأمْسكَ الفَضلَ مِن كلامِه.

'The believer is he whose earnings are pure, whose character is beautiful, whose conscience is clean, who gives away whatever is surplus from his wealth, and guards whatever is surplus from his speech.'

Source: al-Kafi, p. 235, no. 18