Peter Brown at Lapham's Quarterly:
When Christians of late antiquity thought of religious giving, they went back to what for them was the beginning—to the words of Jesus. The words of Jesus to the Rich Young Man described a transfer of “treasure” from earth to heaven: “Jesus said to him, ‘If you would be perfect, go, sell what you possess and give to the poor, and you will have treasure in heaven.’ ”
Jesus repeated this challenge to his disciples: “Sell your possessions and give alms; provide yourselves with purses that do not grow old, with a treasure in the heavens that does not fail, where no thief approaches and no moth destroys.”
The transfer of treasure from earth to heaven was also current in Jewish circles. In the Jerusalem Talmud of the late fourth century, there is a story about King Monobazos, the Jewish king of Adiabene on the Euphrates. He was said to have spent his fortune providing food for the poor in Jerusalem. His infuriated relatives accused him of living up to his name, which was derived from the word bazaz—“to plunder.” Monobazos was plundering his earthly inheritance. He answered them: “My fathers laid up treasure for below, but I have laid up treasures for above. They laid up treasures in a place over which the hand of man may prevail: I in a place over which no hand can prevail.”
more here.