Explanation:

The body of the Human Incarnation in which the God-charged soul exists is called as kshetram. Kshetram is the sacred place having a temple of God and in which God is believed to exist in the statue. If you take Kashi, it is called as a kshetram or a pious place because it is believed that Lord Shiva exists in the Lingam present in the temple at Kashi. Though the same Shiva Lingam exists in any temple present in any other city, it is not called as a Kshetram because the existence of Lord Shiva in the Lingam of the other city is not believed. Hence, the bodies of ordinary human beings are called by the word shariram. The same body and the same soul exist in the Human Incarnation also. But since God exists in the soul of the Human Incarnation, the body of the Human Incarnation is called as kshetram like Kashi city. Even though, the same body and the same soul exist in other human beings also, those bodies are not called as kshetram, since God does not exist in those souls. In the Gita, it is said that the body of Krishna is called as kshetram.

[1] The common Hindu belief is that God exists only in the statues of God in temples that are located in some special sacred places that are called as kshetrams. Other idols or statues are considered to be only representative symbols of God, in which God does not actually exist.