mighty men. mighty ones, or warriors. Compare 2 Samuel 23:8; 1 Kings 1:8; 1 Kings 1:10.
made red. reddened [with blood].
are in scarlet. [are clad] in scarlet, as were the armies of the Persians.
the chariots shall be... torches: or, with the flashing of steel the chariots [glitter].
fir trees. Put by Figure of speech Metonymy (of Cause), App-6, for the spears or lances made from them.