Is relationship between father and son eternal?
In a way yes. Their relation is eternal because son is said to be the own self of the father, his atma.
angad angat sambhavasi
atma vai putra-namasi
sañjiva saradah satam
“You have taken birth from my various limbs and have arisen from my very heart. You are my own self in the form of my son. May you live through a hundred autumns.” This verse appears in the Satapatha Brahmana (22.214.171.124), Kaushitaki brahmana and the Brhad-aranyaka Upanisad (6.4.8).
atma vai putra utpanna
tasmad asya bhaved vakta
The Supreme Lord said: The Vedas instruct us that one’s own self takes birth again as one’s son. Thus let Romaharsana’s son become the speaker of the Puranas, and let him be endowed with long life, strong senses and stamina.
Thus, there are some injunctions in the shastras which show that the self itself takes birth as a son. Hence the relation is of soul and not of flesh alone.
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