What rises as a sweet savour is the smoke of something valuable freely given up. The offering is drawn from the herd and the flock, from a man's own store of wealth, and it is burned rather than hoarded. The point is the giving and not the keeping. A person orders his life by placing his best on the altar and aiming it above himself. Whatever you refuse to sacrifice ends up owning you.
And the offering here is freewill. No one forces it; a man decides on his own to surrender part of what he has, because he has committed himself to something above his own appetite. The vow, the feast, the free gift all point the same way. Give up what is precious, deliberately and without being made to, and that willing loss is what lifts a life out of mere consumption into meaning.