Tao Te Ching - Chapter Seven
Heaven is everlasting and earth is enduring.
The reason that they are everlasting is because they do not exist for themselves.
Hence, they are long lived.
Thus, although the saint puts himself last, finds himself in the lead.
Although he is not self-concerned, finds himself accomplished.
It is because he is not focused on self-interests and hence can fulfill his true nature.
The Way of a saint is to act naturally without contention.