Narasimhapurana 36.2

36.2

yathā matsyena rūpeṇa dattā vedāḥ svayaṃbhuve
madhukaiṭabhau ca nidhanaṃ prāpitau ca mahātmanā //

How in the form of a fish the Vedas were given to Svayambhū, / and Madhu and Kaiṭabha were brought to destruction by the Great-souled One;