Life is only thirty thousand days. What does it mean to borrow a pair of skins?

This sentence means that a person's life is only 30 thousand days, and we just borrowed a pair of skins from heaven. Once a person leaves this world, there is nothing. Don't haggle over everything, just let nature take its course. Calm down, lose your cool. A healthy body is the most important thing, and you can live happily every day.