Don't rest more in a sad diet, and don't covet your own wealth; If this thing can be kept conservative, it will shine like a star in a cold palace. What does this poem mean?

Don't have too much sadness and body diet. Remember not to be greedy for money that is not your own. If this kind of thing (such as morality, principles, kindness and other qualities) can be maintained often, it is like starlight shining into that cold palace.

It means that if you reduce negative emotions, eat properly, not be greedy for money, and keep a good attitude or quality, you will have a brilliant life.