This thing or property naturally participates then in the inviolability of my person.

For instance, I take possession of an object which has become necessary and useful in the outward manifestation of my liberty.

I say, 'This object is mine since it belongs to no one else; consequently, I possess it legitimately.' So the legitimacy of possession rests on two conditions.
First, I possess only as a free being.

Suppress free activity, you destroy my power to labor.

Now it is only by labor that I can use this property or thing, and it is only by using it that I possess it.