The way of everlasting life is a main focus of daoist practice. To go along this attitude the daoist practice are quite many depends on the school the adept is following. But the philosophy is the same. Everlasting life means not the bodily aspect. The name Immortal is for many people confusing and leads to wrong action if deeper understanding is missing.
Here are few examples for a better understanding about daoist exercises. The text is written by Xu Congshi, disciple of Wei Boyang.
The three jewels, the real crux
The ear,the eye, the mouth- these three jewels,
block and stop them up,do not let them gape.
The truth in man lies at the very depths,
He roams wide yet guards a proper compass within.
Sight and hearing are both crooked and winding,
They function entirely together
As the pivot and lynchpin or the self,
Their movement never exhausted.
Bank up and guard the sight within,
Do not employ the ears in hearing,
Close the mouth to chattering,
With rare words out of the teeming void.
These three are the crux of the affair-
To be with a relaxed body, resting in an empty room,
Abandon the will and return to the void,
And without thinking thus find constancy.
Let signs of difficulty promote your change,
And preserve one mind without rebelling:
In bed the spirit cradled in your arms,
Alive and alert to its care or neglect.
It identifies the three keys to the inner development of an Elexir- the ear, the eye and the mouth. They correspond to the internal vitality or body essences:
Jing > body essence
Qi > vital energy
Shen > Spirit
During one`s cultivation lowering down the sensory organs. Means just reacting less or even not (mastership) of whats going on. The meaning is not to become a stone the meaning is to stay focused and relaxed within the body whatever is coming across. If you stay in this state of mind the so called „Golden Elexir“ get created. This can be done because the mind stays calm all the time and you are beyond the point where Yin and Yang gets created. Not only in meditation you should get this point, no also during the hole daily action it is also called: „Refining the Elexir or Inner alchemy“