Srimad Bhagavatam Canto 04, Chapter 28, Text 24

SB 4.28.24

purim vihayopagata
 uparuddho bhujangamah
yada tam evanu puri
 visirna prakrtim gata
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The serpent, who had already been arrested by the soldiers of Yavana-raja and was out of the city, began to follow his master along with the others. As soon as they all left the city, it was immediately dismantled and smashed to dust.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
When the living entity is arrested, all his followers — namely the life air, the senses and sense objects — immediately leave the lump of matter, the body. When the living entity and his companions leave, the body no longer works but turns into basic material elements — earth, water, fire, air and ether. When a city attacked by enemies is vacated by its inhabitants, the enemy immediately takes advantage of that city and bombards it to smash the whole thing to dust. When we say, “Dust thou art, and unto dust thou shall return,” we refer to the body. When a city is attacked and bombarded by enemies, the citizens generally leave, and the city ceases to exist.
It is a foolish person who engages in improving the condition of a city without caring for the citizens or inhabitants. Similarly, a living entity who is not properly enlightened in spiritual knowledge simply takes care of the external body, not knowing that the spirit soul is the principal factor within the body. When one is advanced in spiritual knowledge, the spirit soul is saved from eternal transmigration. The Bhagavatam considers those who are attached to their bodies to be like cows and asses (sa eva go-kharah). The cow is a very innocent animal, and the ass is a beast of burden. One who labors under the bodily conception simply works like an ass and does not know his self-interest. It is therefore said:
yasyatma-buddhih kunape tri-dhatuke
 sva-dhih kalatradisu bhauma ijya-dhih
yat-tirtha-buddhih salile na karhicij
 janesv abhijñesu sa eva go-kharah
“A human being who identifies this body made of three elements with his self, who considers the by-products of the body to be his kinsmen, who considers the land of birth worshipable, and who goes to a place of pilgrimage simply to take a bath rather than meet men of transcendental knowledge there, is to be considered like an ass or a cow.” (Bhag. 10.84.13)
Human civilization devoid of Krsna consciousness is simply a civilization of lower animals. Sometimes such a civilization may study the dead body and consider the brain or the heart. However, no part of the body is important unless the spirit soul is present. In a modern civilization of cows and asses, scientists try to search out some value in the brain or heart of a dead man.
Srimad Bhagavatam Canto 04, Chapter 28, Text 23
Srimad Bhagavatam Canto 04, Chapter 28, Text 25