Thou girdest thyself (ezōnnues seauton). Imperfect active of customary action of zōnnuō, old verb, in N.T. only here and Act 12:8. So as to periepateis (walkedst) and ētheles (wouldest), two other imperfects of customary action.
When thou shalt be old (hotan gērasēis). Indefinite temporal clause with hotan and the first aorist active subjunctive of gēraskō, old verb to grow old, in N.T. only here and Heb 8:13, “whenever thou growest old.”