Set Foot Meaning

(idiomatic, rhetorical with on) To step onto

Example: 1898, J. Meade Falkner, Moonfleet Chapter 4
  Yet had I scarce set foot in the passage when I stopped, remembering how once already this same evening I had played the coward, and run home scared with my own fears.
After the boat capsized, I thought that I would never set foot on dry land again.