There was no one in the group who was in need. Those who owned fields or houses would sell them, bring the money received from the sale,

For the churches in Macedonia and Achaia have freely decided to give an offering to help the poor among God's people in Jerusalem.

That decision was their own; but, as a matter of fact, they have an obligation to help them. Since the Jews shared their spiritual blessings with the Gentiles, the Gentiles ought to use their material blessings to help the Jews.