For since he who pays a tithe keeps nine parts to himself, and
surrenders the tenth to another, as the number ten is the sign
of perfection, as being, in a sort, the terminus of all numbers which
mount from one to ten, it follows that he who pays a tithe bears
witness to his own imperfection and to the perfection of another.
surrenders the tenth to another, as the number ten is the sign
of perfection, as being, in a sort, the terminus of all numbers which
mount from one to ten, it follows that he who pays a tithe bears
witness to his own imperfection and to the perfection of another.
Summa Theologica