{Are rusted} (kati(9374)ai). Perfect passive indicative
(singular for chrusos and arguros are grouped as one) of
katio(935c), late verb (from ios, rust) with perfective sense of
kata, to rust through (down to the bottom), found only here,
Sir. 12:11, Epictetus (_Diss_. 4, 6, 14). {Rust} (ios). Poison
in  Jas 3:8  Ro 3:13  (only N.T. examples of old word). Silver
does corrode and gold will tarnish. Dioscorides (V.91) tells
about gold being rusted by chemicals. Modern chemists can even
transmute metals as the alchemists claimed. {For a testimony}
(eis marturion). Common idiom as in  Mt 8:4  (use of eis with
accusative in predicate). {Against you} (humin). Dative of
disadvantage as in  Mr 6:11  (eis marturion autois) where in
the parallel passage ( Lu 9:5 ) we have eis marturion ep'
autous. "To you" will make sense, as in  Mt 8:4  10:18 , but
"against" is the idea here as in  Lu 21:13 . {Shall eat}
(phagetai). Future middle (late form from ephagon) of
defective verb esthi(935c), to eat. {Your flesh} (	as sarkas). The
plural is used for the fleshy parts of the body like pieces of
flesh ( Re 17:16  19:18,21 ). Rust eats like a canker, like
cancer in the body. {As fire} (h(9373) pur). Editors differ here
whether to connect this phrase with phagetai, just before (as
Mayor), for fire eats up more rapidly than rust, or with the
following, as Westcott and Hort and Ropes, that is the eternal
fire of Gehenna which awaits them ( Mt 25:41  Mr 9:44 ). This
interpretation makes a more vivid picture for eth(8873)aurisate (ye
have laid up, first aorist active indicative of 	h(8873)auriz(935c),  Mt
6:19  and see  Pr 16:27 ), but it is more natural to take it with
phagetai.