James warns the wealthy that their riches 'have rotted' (5:2), using vivid imagery of decomposition to illustrate the worthlessness of hoarded wealth. While wealth itself doesn't literally rot, the verb evokes garments moth-eaten and treasures corroded—material goods subject to decay. The perfect tense suggests a completed state: their wealth has already rotted in God's perspective, even if they don't see it yet. This prophetic critique echoes Jesus's teaching about treasures on earth that moths and rust destroy (Matthew 6:19).