Śrīmad Bhāgavatam 1.8.33

apare vasudevasya

devakyāḿ yācito 'bhyagāt

ajas tvam asya kṣemāya

vadhāya ca sura-dviṣām

SYNONYMS

apare — others; vasudevasya — of Vasudeva; devakyām — of Devakī; yācitaḥ — being prayed for; abhyagāt — took birth; ajaḥ — unborn; tvam — You are; asya — of him; kṣemāya — for the good; vadhāya — for the purpose of killing; ca — and; sura-dviṣām — of those who are envious of the demigods.

TRANSLATION

Others say that since both Vasudeva and Devakī prayed for You, You have taken Your birth as their son. Undoubtedly You are unborn, yet You take Your birth for their welfare and to kill those who are envious of the demigods.

PURPORT

It is also said that Vasudeva and Devakī, in their previous birth as Sutapā and Pṛśni, underwent a severe type of penance to get the Lord as their son, and as a result of such austerities the Lord appeared as their son. It is already declared in the Bhagavad-gītā that the Lord appears for the welfare of all people of the world and to vanquish the asuras, or the materialistic atheists.