Devibhagavatapurana 11.17.17

11.17.17

tata udvāsayeddevīmuttametyanuvākataḥ |
na gāyatrīṃ japedvidvāñjalamadhye kathañcana ||

Then raise the Gâyatrî placed before on the heart (seat) by the mantra “Gâyatrasyai kapadî Dvîpadî, etc., and then bid farewell to Her after bowing down to Her and repeating the mantra “Omuttame S’ikhare Devî bhûmyâm parvata mûrdhani Brâhmana ebhyobhya anujñâtâ Gachcha Devî yathâsukham” on the highest top of the mountain summit in earth (i.e., on the Meru mountain) dwells the goddess Gâyatrî. Being pleased with Thy worshippers go back, O Devî! to Thy abode as it pleaseth Thee.” (See page 110, The Daily Practices of the Hindus.)
The wise men never mutter nor recite the Gâyatrî mantra within the water. For the Maharsis say that the Gâyatrî is fire-faced (agnimukhî). After the farewell shew again the following mudrâs:-- Surabhi Jñân, Sûrpa, Kûrma, Yoni, Padma, Linga and Nirvâna Mudrâs.
Then address thus:-- “O Devî! O Thou who speakest pleasant to Kas’yapa! O Gâyatrî! Whatever syllables I have missed to utter in making Japam, whatever vowels and consonants are incorrectly pronounced, I ask Thy pardon for all my above faults.” O Nârada! Next one ought to give peace offerings to the Gâyatrî Devî.