Bede

And I separated twelve of the chiefs of the priests, etc. It has been frequently said that the silver and gold and vessels sent from Babylon to Jerusalem signify souls, which are converted to the Lord from the confusion and errors of this world. Hence, Ezra appropriately entrusts such vessels to the priests, who are to carry them to Jerusalem; for it is necessary that through the hands of the priests, those who desire to reach the companionship of the holy Church are washed in baptism and consecrated to the Lord. …

Commentary on Ezra and Nehemiah ↗