What is the significance that the beams of our house are cedars?
Rashi: This is praise of the Mishkan.
Seforno: The Chachamim of our generations are tall in Chachmah, Torah and Mitzvos.
Malbim (Melitzah): The verse depicts the prophetic clinging of the Nefesh with the Unlimited based on Hashem's command to build the Beis ha'Mikdash. It is an intermediary between the Unlimited and Unbounded, and the constricted and bounded. When He wants, the Unlimited makes [His] honor dwell on Jewish Nefashos, which are the ultimate constriction. The Nefesh dwells in a small attic, like a man's palm 1 ! As a compromise, they will build for Him a house of cedars, as if He will abandon His nature (Unlimited and not confined to place) to dwell in a bounded place - on top of the Keruvim, under cedar beams. Also the Nefesh will abandon its nature (constricted in a small place, a square Zeres (three Tefachim), in a body of flesh, sinews and bones at the lowest level). It will dwell and be isolated with its Beloved in a freer and wider place, and in a body stronger than man's body - a body from vegetation, less composite than living bodies. The two extremes will always meet in an intermediate border. To teach this, Shlomo depicted this intermediate place as under cedar beams (cedars are the tallest trees), like the Torah chose the Mishkan 2 . It also depicts the elevation of the element of earth from lowliness to great height.
Malbim (Mashal): Since we will dwell and lodge in the forest, the walls of our house will be the tall forest cedars. Under their shade will be shelter and a place to lie.
What is the meaning of "Rahitenu Berosim"?
Rashi: I am unsure if it is an expression of Kerashim (beams) or Berichim (bolts). We find 'the Rehitim of a man's house testify about him' (Ta'anis 11a).
Seforno: Rahitenu are the Talmidim.
Malbim (Melitzah): Rahitenu are conduits via which flows water from pine trees. Their branches spread wide. I.e. the flow will pass via pine trees on the roof of this Mikdash. The conduits will be for basins and Brachah, to make flow influence and Ruchniyus onto the land and sad bodies thirsty for rain of Shamayim, dew of light and physical gifts, and to revive them with higher water, water of Chesed and Kedushah.
Malbim (Mashal): The wide branches and leaves of pine trees will cover our bed and divert the water to the side, lest rain descend on us.
