'Thirty' in the Bible

Then he made the sea of molten metal, from brim to brim [it was] ten cubits, completely round. And [it was] five cubits in height, and {its circumference measured} thirty cubits.

And Jehoiada grew old and full of days, and he died; [he was] one hundred and thirty years old at his death.

Then Josiah provided for the {lay people} sheep, lambs, and young goats, all for the Passover for all who were found [there], to the sum of thirty thousand, along with three thousand bulls. These [were] the possession of the king.