Śatapatha Brāhmaṇa ("of a hundred paths") 9.2.3.50

9.2.3.50

atho āhuḥ | prajāpatirevaitam priyam putramurasyādhatta iti sa yo haitadevaṃ vedā haivam priyam putramurasi dhatte

Moreover, they say, 'It is Pragâpati himself who takes this (Agni) as his dear son to his bosom;' and verily, whosoever so knows this, takes thus a dear son to his bosom.