Gargya said: 'The person that is in the fire (and in the heart), that I adore as Brahman.' Agatasatru said to him: 'No, no! Do not speak to me on this. I adore him as powerful.' Whoso adores him thus, becomes powerful, and his offspring becomes powerful.

In plain words: Gargya said he worships the person in fire as Brahman. The king said he already honors that one as powerful, and whoever does so becomes strong, and so do his children.