Eknath Easwaran's Commentary
Every one of us has an enormous internal savings account of vitality. In our youth we have a margin for experimenting with this vital energy account, for learning through trial and error how it works. But after the age of, say, twenty-five, we need to begin to learn how to live on the interest of this account and not consume the principal. We need to be very careful about which desires we pursue, and not waste our energy in resentment or in fear.
Yet grace adds a whole new dimension to this account. The divine core in all of us is the very source of vital energy, and it is infinite. The more we draw on this divine deposit of wealth – so long as we are drawing from it not for ourselves, but in the service of all life – the more it is replenished.