What is "Beis Ya'ar ha'Levanon"?
Rashi citing Targum Yonasan: A cold house for the king. Radak - the custom of kings was to build a house in the forest to cool off in summer. Shlomo built it in a known forest in Eretz Yisrael called Levanon.
'Rashi' (Divrei ha'Yamim II, 9:16): It is a big house in Yerushalayim. It was made from the many big trees in Levanon. Shlomo put his shields there (Divrei ha'Yamim II, 9:6) and Shishak took them - "va'Tabet ba'Yom ha'Hu El Neshek Beis ha'Ya'ar" (Yeshayah 22:8).
Gra: It is called Ya'ar ha'Levanon, for there were many cedar pillars, and it resembled the forest called Ya'ar ha'Levanon.
How were the pillars spaced?
Rashi: The rows of pillars went along the length of the house.
Gra: Each row of pillars went along the width of the house. Each row was two and a half Amos wide, and there were 30 Amos of stone between rows. 1 The pillars occupied 10 Amos, and the spaces between them totaled 90, making 100 in all. Each row was 50 long.
Also Malbim explains that the rows went along the width of the house, and a third of the house's length was between adjacent rows, just he did not specify the width of the pillars. (PF)
What is "Kerusos Arazim Al ha'Amudim"?
Rashi: The cedar beams went on top 1 of the pillars, and joined one pillar to the next, like lintels. Radak - they are big beams called Marish (Gitin 55a).
Radak citing Targum Yonasan: The corners of the beams were on the pillars.
Gra: Each pillar was covered with cedar planks from bottom to top.
Malbim: The cedars joined the pillars along the width of the house, in order to put the roof on them.
Hagahah (Tzuras ha'Bayis): Perhaps the beams were not on the pillars, rather, they were fastened to the tops and connected each pillar to the next pillar in the row.
