Devibhagavatapurana 2.9.24

Devībhāgavatapurāṇa 2.9.24

guravaḥ pūjitā bhaktyā hutaṃ japtaṃ tapaḥ kṛtam |
adhītāstvakhilā vedā gāyatrī saṃskṛtā yadi ||