50 Furthermore, a person's superfluous income, that is, income which he does not need to sustain life fittingly and with dignity, is not left wholly to his own free determination. Rather the Sacred Scriptures and the Fathers of the Church constantly declare in the most explicit language that the rich are bound by a very grave precept to practice almsgiving, beneficence, and munificence.
Source: Quadragesimo Anno (Vatican.va)