“Your gold and silver is cankered; and the rust of them shall be a witness against you, and shall eat your flesh as it were fire. Ye have heaped treasure together for the last days.”
King James Version (KJV)
5:3 The canker of them - Your perishing stores and motheaten garments. Will be a testimony against you - Of your having buried those talents in the earth, instead of improving them according to your Lord's will. And will eat your flesh as fire - Will occasion you as great torment as if fire were consuming your flesh. Ye have laid up treasure in the last days - When it is too late; when you have no time to enjoy them.
Jas 5:3 Your gold and silver is cankered. Rusted from disuse. These metals do not literally rust, but do tarnish from long disuse. The idea is that they show they have been hoarded, not used. And the rust of them shall be a witness against you. The tarnish shows that you have hoarded instead of using. And shall eat your flesh as it were fire. They shall punish you, as though heated by fire and eating into your flesh. This hoarded wealth will curse the possessor. Ye have heaped up treasure. Instead of laying up treasure in heaven you have continued to pile up earthly treasure to the last, a matter of extreme folly. For the last days. What James then thought of as "the last days", the end of his nation, country and Jerusalem, was close at hand.