1 Kings (Author Compiled by Isaiah and Jeremiah from records of Nathan, Gad, Iddo, Ahijah, Jehu and others.)
6:2And the house which king Solomon built for the LORD, the length thereof was threescore cubits, and the breadth thereof twenty cubits, and the height thereof thirty cubits.
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.