'Strap' in the Bible

Then David said to his men, "Each man strap on his sword!" So each one strapped on his sword, and David also strapped on his sword. About four hundred men went up after David, while two hundred remained with the baggage.

And he was preaching, saying, "One [who is] more powerful than I is coming after me, of whom I am not worthy to bend down [and] untie the strap of his sandals.

John answered them all, saying, "I baptize you with water, but the one who is more powerful than I [am] is coming, of whom I am not worthy to untie the strap of his sandals. He will baptize you with the Holy Spirit and fire.

the one who comes after me, of whom I am not worthy {to untie} the strap of his sandal!"