In these verses, James is addressing wealthy individuals who have hoarded their wealth and exploited their workers. He is warning them that their wealth will ultimately be their downfall and that their actions have not gone unnoticed by God.
First, James speaks of the "corrosion" of the rich individuals' gold and silver. This can be interpreted both literally and metaphorically. Literally, gold and silver can corrode over time, but metaphorically, James is suggesting that their wealth is tarnished or corrupted. He goes on to say that this corrosion will be a testimony against them, meaning that their wealth will ultimately be used as evidence of their wrongdoing. The metaphorical meaning of corrosion is further emphasized when James says that the corrosion will "eat your flesh like fire," indicating that their wealth will ultimately be destructive to them.
James then accuses the wealthy individuals of hoarding their wealth in the "last days." This could refer to the end of the world or the end of their own lives, but either way, James is suggesting that they are storing up their wealth for a time when it will be of no use to them. He is warning them that their focus on wealth and material possessions is misplaced and that they should be focusing on more meaningful pursuits.
Next, James speaks of the laborers who have been exploited by these wealthy individuals. He says that they have "kept back [their] wages by fraud," indicating that they have not paid their workers fairly. James says that the cries of these workers have "entered into the ears of the Lord of Armies," meaning that God is aware of their suffering and will ultimately hold the wealthy individuals accountable for their actions.
Finally, James accuses the wealthy individuals of living "delicately on the earth" and "taken [their] pleasure." This suggests that they have been living selfishly, indulging in their own desires and ignoring the needs of others. James compares their behavior to that of those who "nourished [their] hearts as in a day of slaughter," indicating that their actions are leading to their own destruction.
In summary, James 5:3-5 is a warning to wealthy individuals who have hoarded their wealth and exploited their workers. James suggests that their wealth is ultimately corrupt and will be their downfall, and that God is aware of their actions and will hold them accountable. He also suggests that they should be focusing on more meaningful pursuits rather than indulging in their own desires.
James 5:3-5. You have laid up your treasure in the last days. Behold, the wages of the laborers who mowed your fields, which you have kept back by fraud, cry out, and the cries of those who reaped have entered into the ears of the Lord of Armies. You have lived delicately on the earth, and taken your pleasure. You have nourished your hearts as in a day of slaughter.