gird up one's loins

Likely a Hebraism, often used in the King James Bible (e.g., 2 Kings 4:29). Literally referred to the need to strap a belt around one's waist, i.e. when getting up, in order to avoid the cloak falling off; or otherwise before battle, to free the legs for running.

• "Man came into this world, not to sit down and muse, not to befog himself with vain subtleties, but to gird up his loins and to work."
• "Then Tom girded up his loins, so to speak, and went to work to “get his verses.”"
• "Then Susan said briskly, "Well, we must just gird up our loins and pitch in.""
• "King Gyanendra must gird up his loins and prepare himself for all exigencies."

• brace oneself
• eat one's Wheaties
• roll up one's sleeves
• shape up
• steel oneself
• suck it up

• batten down the hatches
• tighten one's belt