They were happy to do this, and really they owe it to them. These who are not Jews have shared in the Jews’ spiritual blessings, so they should use their material possessions to help the Jews.
It is as if some of the branches from an olive tree have been broken off. You non-Jewish people are like the branch of a wild olive tree that has been joined to that first tree. You now share the strength and life of the first tree, the Jews.