Hiranyakeshigrihyasutra 1.2.8.16

1.2.8.16

kāṇḍopākaraṇe kāṇḍavisarge ca \ sadasaspatimadbhutaṃ priyamindrasya kāmyam \ saniṃ medhāmayāsiṣam \ svāhā \ iti kāṇḍarṣirdvitīyaḥ \ imaṃ me varuṇa \ tattvā yāmi \ tvaṃ no agne \ sa tvaṃ no agne \ tvamagne ayāsi \ prajāpate \ yadasya karmaṇotyarīricam \ iti ca \ atraike jayābhyātānānrāṣṭrabhṛta ityupajuhvati yathā purastāt \16\ \\8\\

At the beginning and on the completion of the study of a Kânda (of the Black Yagur-veda he sacrifices) with (the verse), 'The lord of the seat, the wonderful one, the friend of Indra, the dear one, I have entreated for the gift of insight. Svâhâ!'
In the second place the Rishi of the Kânda (receives an oblation).
(Then follow oblations with the verses), 'This, O Varuna;' 'For this I entreat thee;' 'Thou, Agni;' 'Thus thou, Agni;' 'Thou, Agni, art quick;' 'Pragâpati!' and, 'What I have done too much in this sacrifice.' Here some add as subordinate oblations the Gaya, Abhyâtâna, and Râshtrabhrit (oblations) as above.
End of the Second Patala.