John Gill Commentary 1 Kings 7

But Solomon was building his own house thirteen years He made more haste with the house of God than with his own, for that was but seven years in building; which showed greater regard to the honour of God than to his own glory, or even convenience; nor was this built till after that:

and finished all his house ; or houses he undertook to build, the singular for the plural; even the house of God, his own palace, and that for the daughter of Pharaoh, and that which is next mentioned, which were in all twenty years building, (1 Kings 9:10) .

He built also the house of the forest of Lebanon
Besides the temple, his own palace, and the queen's; so called, not because it was built on Mount Lebanon, which lay at the northern border of the land, at a great distance from Jerusalem, whereas this was both a magazine of arms, and a court of judicature, (1 Kings 7:7) ; see (1 Kings 10:17) (Isaiah 22:8) ; neither of which can be supposed to be far from Jerusalem; but because not only it was built of the cedars of Lebanon, but in a situation, and among groves of trees which resembled it; it seems to have been a summer house; and so the Targum calls it, a royal house of refreshment:

the length thereof [was] an hundred cubits, and the breadth thereof
fifty and the height thereof thirty cubits ;
so that it was in every measure larger than the temple; and, there was good reason for it, since into that only the priests entered; whereas into this went not only Solomon's family but his courtiers and nobles, and all foreign ambassadors, and whoever had any business with him, which required various rooms to receive them in:

upon four rows of cedar pillars ;
or piazzas:

with cedar beams upon the pillars ;
which laid the floor for the second story.

And it was covered with cedar above the beams, that lay on
forty five pillars, fifteen in a row. On the second floor were three rows of pillars, fifteen in a row, which made forty five, that stood to east, north, and south; and upon these pillars beams, which were the floor of the third story, over which was a roof of cedar wood.

And there were windows in three rows
Both in the second and third stories, east, north, and south, there being none in the west, where the porch stood:

and light was against light in three ranks ;
or the windows, through which light was let, answered to each other.

And all the doors and posts were square with the windows

The doors into the several stories and apartments, and the posts and lintel of them, and the windows over them, were all square:

and light was against light in three ranks ;

they answered one another as before.