dehe pañcatvam apanne
dehi karmanugo ’vasah
praktanam tyajate vapuh
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When the present body turns to dust and is again reduced to five elements earth, water, fire, air and ether the proprietor of the body, the living being, automatically receives another body of material elements according to his fruitive activities. When the next body is obtained, he gives up the present body.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
This is confirmed in Bhagavad-gita, which presents the beginning of spiritual understanding.
dehino ’smin yatha dehe
kaumaram yauvanam jara
dhiras tatra na muhyati
“As the embodied soul continually passes, in this body, from boyhood to youth to old age, the soul similarly passes into another body at death. The self-realized soul is not bewildered by such a change.” (Bg. 2.13) A person or an animal is not the material body; rather, the material body is the covering of the living being. Bhagavad-gita compares the body to a dress and elaborately explains how one changes dresses one after another. The same Vedic knowledge is confirmed here. The living being, the soul, is constantly changing bodies one after another. Even in the present life, the body changes from childhood to boyhood, from boyhood to youth, and from youth to old age; similarly, when the body is too old to continue, the living being gives up this body and, by the laws of nature, automatically gets another body according to his fruitive activities, desires and ambitions. The laws of nature control this sequence, and therefore as long as the living entity is under the control of the external, material energy, the process of bodily change takes place automatically, according to one’s fruitive activities. Vasudeva therefore wanted to impress upon Kamsa that if he committed this sinful act of killing a woman, in his next life he would certainly get a material body still more conditioned to the sufferings of material existence. Thus Vasudeva advised Kamsa not to commit sinful activities.
One who commits sinful activities because of ignorance, tamo-guna, obtains a lower body. Karanam guna-sango ’sya sad-asad-yoni janmasu (Bg. 13.22). There are hundreds and thousands of different species of life. Why are there higher and lower bodies? One receives these bodies according to the contaminations of material nature. If in this life one is contaminated by the mode of ignorance and sinful activities (duskrti), in the next life, by the laws of nature, one will certainly get a body full of suffering. The laws of nature are not subservient to the whimsical desires of the conditioned soul. Our endeavor, therefore, should be to associate always with sattva-guna and not indulge in rajo-guna or tamo-guna (rajas-tamo-bhavah). Lusty desires and greed keep the living entity perpetually in ignorance and prevent him from being elevated to the platform of sattva-guna or suddha-sattva-guna. One is advised to be situated in suddha-sattva-guna, devotional service, for thus one is immune to the reactions of the three modes of material nature.