Matthew Poole and continuators on Ezra 1:6

6 And all they that were about them, strengthened their hands with vessels of silver, with gold, with goods, and with beasts, and with precious things, besides all that was willingly offered.

Either because they had embraced, or at least favoured the Jewish Religion, concerning which they were instructed by the Israelites that had now for a long time dwelt among them: or rather, that they might hereby gratifie the Kings humour, and purchase his favour: for they perceived him to be hearty and forward in the work.

Marginal references: That is, helped them.