John Gill Commentary Ezra 6:4

"with three courses of great stones, and a course of new timber: and let the expenses be given out of the king`s house." — Ezra 6:4 (ASV)

With three rows of great stones
Which Jarchi interprets of the walls of it, and these stones of marble; and so Ben Melech:

and a row of new timber ;
of cedar wood upon the rows of stone, see (1 Kings 6:36) or for the lining and wainscoting the walls:

and let the expenses be given out of the king's house ;
treasury, or exchequer; but it does not appear that this part of the decree was observed, at least hitherto; but the Jews built at their own expense, and perhaps did not exactly observe the directions given as to the dimensions of the house.