Why does it mention that they bear swords?
Seforno (6): Even in the days of Shlomo, that I gave Shalom on Yisrael, they needed weapons.
Malbim (Melitzah): These Giborim defeat the Nefesh for two reasons. (a) Due to their nature, the Nefesh cannot separate from them. It is incarcerated within them, like a Gibor bearing a sword. He wins, due to his strength. (b) Refer to 3:8:2:3.
Why does it say that they are "Melumedei Milchamah"?
Rashi: They are trained in the war of Torah. Similarly, the Kohanim who camp around the Mishkan are trained in their Avodah.
Seforno: They are used to it. This is like "va'Yilmad Litraf Teref" (Yechezkel 19:3).
Malbim (Melitzah): These Giborim defeat the Nefesh also due to routine. They constantly fight against its Ruchniyus via war strategies. They immerse it in physicality, like a trained warrior wins via war strategies. If so, how did the Nefesh leave the bed?!
Why does it say "Ish Charbo Al Yerecho [mi'Pachad ba'Leilos]"?
Rashi: His weapons are tradition and Simanim to help him to remember the text and tradition, lest he forget.
Seforno: His sword is at his side.
Malbim (Melitzah): This answers how she fled from the bed. Due to the terror that fell on the body's limbs (when Divine Ru'ach comes on Nevi'im, there is great fear on them. Their limbs dissemble, their thoughts are befuddled and the build of their bodies melts - "Pachad Kera'ani u'Re'adah" (Iyov 4:14), "va'Epol Al Panai" (Yechezkel 1:28). So the Rambam wrote in Hilchos Yesodei ha'Torah.) Due to this, their swords returned to their thighs and their nature and physical strength was Batel, and they could not stop this Bas Shamayim from separating from them. The sword remained on the thigh, for physical strength remained only in the thigh. It is the end of the body 1 and the place of procreation. This is why "va'Yiga b'Chaf Yerecho" (Bereishis 32:26) - there Yakov did not separate from physicality when he fought the angel, like the Zohar says and like I explained there (refer to Bereishis 32:26:2:8).
Malbim (6, Mashal): This answers how she fled from the bed. The Giborim could not raise a sword against her. The sword returned to its sheath because fear of the night fell on them.
I do not understand how it is the end of the body. (PF)
What do we learn from "[Ish Charbo Al Yerecho] mi'Pachad ba'Leilos"?
Torah Temimah citing Yevamos 109b: A judge should view himself as if a sword is between his thighs, and Gehinom is open beneath him. The judges fear Gehinom, which is like night.
Gitin 68b: Shlomo captured Ashmedai (the king of the demons) in order to get a special worm needed to build the Mikdash. Later, Ashmedai was able to cast Shlomo 400 Parsa'os (about 1600 kilometers). He assumed the appearance of Shlomo, and acted like king. Later, Shlomo returned with a ring and chain with Hashem's name (like was initially used to capture Ashmedai). Ashmedai fled in fear. Still, Shlomo forever remained afraid of him.
Rashi: Lest they forget, and troubles will come on them. This is like "Nashku Var Pen Ye'enaf v'Sovdu Derech" (Tehilim 2:12).
Malbim: Refer to 3:8:3:3-4.