How does he gird with a sword?
Rashi: It is [Chachmah] to fight the war of Torah.
Radak: Some swords are girded on the loins - "v'Alav Chagor Cherev Metzumedes Al Masnav" (Shmuel II, 20:8). Some are girded on the thigh, like Ehud's - "va'Yachgor Osah
Why does it say "Gibor"?
Radak, Malbim: This calls to him; you are a Gibor.
Why does it say "Hodcha va'Hadarecha"?
Rashi, Shabbos 63a #1: This [the war of Torah] is your glory and beauty.
Radak: The sword is your glory and beauty. Malbim - Gevurah is one of the attributes needed for a king. You gird with a sword not for war, rather, because it is part of the beauty of kingship.
Radak (from Shabbos 63a #2): This teaches that a sword is an ornament (it is considered like clothing, and not carrying a load; the same applies to other weapons worn on the body).
Malbim (Derech ha'Muskal): The intellect's glory and beauty is that it can bring proofs for foundations of truth.