Albert Barnes Commentary 1 Kings 7:6

"And he made the porch of pillars; the length thereof was fifty cubits, and the breadth thereof thirty cubits; and a porch before them; and pillars and a threshold before them." — 1 Kings 7:6 (ASV)

This was probably the porch of the "House of the Forest." Porches of columns immediately in front of columnar chambers were a favorite feature of Persian architecture. The entire verse should be translated: And he made the porch of the pillars 50 cubits in length, and 30 cubits in breadth, and a porch before them (that is, the pillars), and pillars, and a base or step before them. Most Persepolitan porches had small, pillared chambers set at some distance in front of them.