Bhagavatapurana 3.4.13

3.4.13

purā mayā proktam ajāya nābhye padme niṣaṇṇāya mamādi-sarge /
jñānaṃ paraṃ man-mahimāvabhāsaṃ yat sūrayo bhāgavataṃ vadanti //

13. Of old, in the beginning of creation, the supreme means of knowledge, which discovers to view all My glories, was imparted by Me to Brahma seated on the lotus in My navel, and the wise call it the Bhagavata.