CCC 2446 St. John Chrysostom vigorously recalls this: “Not to enable the poor to share in our goods is to steal from them and deprive them of life. The goods we possess are not ours, but theirs.”¹ “The demands of justice must be satisfied first of all; that which is already due in justice is not to be offered as a gift of charity”:²
When we attend to the needs of those in want, we give them what is theirs, not ours. More than performing works of mercy, we are paying a debt of justice.³

1 St. John Chrysostom, Hom. in Lazaro 2, 5: PG 48, 992.
2 AA 8 # 5.
3 St. Gregory the Great, Regula Pastoralis. 3, 21: PL 77, 87.