'And when (the body) grows weak through old age, or becomes weak through illness, at that time that person, after separating himself from his members, as an Amra (mango), or Udumbara (fig), or Pippala-fruit is separated from the stalk, hastens back again as he came, to the place from which he started, to (new) life.

In plain words: When the body becomes weak from old age or illness, the Self lets go of the limbs, the way a ripe mango or fig drops from its stem. Then it hurries on to a new life.