My dear Lord, when You appeared as Hayagrīva, with the head of a horse, You killed two demons known as Madhu and Kaiṭabha, who were full of the modes of passion and ignorance. Then You delivered the Vedic knowledge to Lord Brahmā. For this reason, all the great saints accept Your forms as transcendental, untinged by material qualities.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
तस्मै भवान् हयशिरस्तनुवं हि बिभ्रद्- वेदद्रुहावतिबलौ मधुकैटभाख्यौ । हत्वाऽऽनयच्छ्रुतिगणांस्तु रजस्तमश्च सत्त्वं तव प्रियतमां तनुमामनन्ति
tasmai bhavān hayaśirastanuvaṃ hi bibhrad- vedadruhāvatibalau madhukaiṭabhākhyau | hatvā''nayacchrutigaṇāṃstu rajastamaśca sattvaṃ tava priyatamāṃ tanumāmananti
SB 7.9.37