Bede

And this is their number: thirty golden bowls, etc. Different types of vessels signify different persons or operations of the faithful. Finally, we read in the Apocalypse that the twenty-four elders had golden bowls full of incense (Rev. 5); and the Scripture explains: These are the prayers of the saints. Therefore, the bowls, which are open, bright vessels, signify the hearts of the simple, who know not how to conceal any deceitful thought within them, but are accustomed to express with a pure tongue what they hold in their mind. …

Commentary on Ezra and Nehemiah ↗