Bg 2.23

nainam chindanti sastrani
nainam dahati pavakah
na cainam kledayanty apo
na sosayati marutah

Word for word: 
na — never; enam — this soul; chindanti — can cut to pieces; sastrani — weapons; na — never; enam — this soul; dahati — burns; pavakah — fire; na — never; ca — also; enam — this soul; kledayanti — moistens; apah — water; na — never; sosayati — dries; marutah — wind.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The soul can never be cut to pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind.

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
All kinds of weapons – swords, flame weapons, rain weapons, tornado weapons, etc. – are unable to kill the spirit soul. It appears that there were many kinds of weapons made of earth, water, air, ether, etc., in addition to the modern weapons of fire. Even the nuclear weapons of the modern age are classified as fire weapons, but formerly there were other weapons made of all different types of material elements. Fire weapons were counteracted by water weapons, which are now unknown to modern science. Nor do modern scientists have knowledge of tornado weapons. Nonetheless, the soul can never be cut into pieces, nor annihilated by any number of weapons, regardless of scientific devices.

The Mayavadi cannot explain how the individual soul came into existence simply by ignorance and consequently became covered by the illusory energy. Nor was it ever possible to cut the individual souls from the original Supreme Soul; rather, the individual souls are eternally separated parts of the Supreme Soul. Because they are atomic individual souls eternally (sanatana), they are prone to be covered by the illusory energy, and thus they become separated from the association of the Supreme Lord, just as the sparks of a fire, although one in quality with the fire, are prone to be extinguished when out of the fire. In the Varaha Purana, the living entities are described as separated parts and parcels of the Supreme. They are eternally so, according to the Bhagavad-gita also. So, even after being liberated from illusion, the living entity remains a separate identity, as is evident from the teachings of the Lord to Arjuna. Arjuna became liberated by the knowledge received from Krishna, but he never became one with Krishna.