'Loins' in the Bible

“He loosens the bond of kingsAnd binds their loins with a loincloth.

For he has covered his face with his fat,Adding layers of fat to his thighs [giving himself up to pleasures],

If his loins have not thanked and blessed me [for clothing them],And if he was not warmed with the fleece of my sheep,

“Now gird up your loins like a man,And I will ask you, and you instruct Me!

“Now gird up your loins (prepare yourself) like a man,And I will ask you, and you instruct Me.

“See now, his strength is in his loinsAnd his power is in the muscles and sinews of his belly.