Having shod (hupodēsamenoi). “Having bound under” (sandals). First aorist middle participle of hupodeō, old word, to bind under (Mar 6:9; Act 12:8, only other N.T. example).
With the preparation (en hetoimasiāi). Late word from hetoimazō, to make ready, only here in N.T. Readiness of mind that comes from the gospel whose message is peace.