Bede

And as for laying the supporting foundations, etc., it is not for us to explain; because neither in the earlier building of the temple nor in the later one is any of these measurements or such work found. Hence it is inferred that Cyrus uttered this of his own accord, and noted the measurement or order of the work as seemed appropriate to him; inasmuch as the temple, as the Words of the Days recount, in the first measure, that is, within the inner walls, had sixty cubits of length, twenty cubits of width. …

Commentary on Ezra and Nehemiah ↗