Hiranyakeshigrihyasutra 2.6.16.6

2.6.16.6

udakumbhaṃ darbhamuṣṭiṃ cādāya prāṅmukho niṣkramya prāco darbhānsaṃstīrya teṣu caturo balīnharati \ ye pārthivāḥ sarpāstebhya imaṃ baliṃ harāmi \ ya āntarikṣāḥ \ ye divyaḥ \ ye diśyāḥ \ iti \6\

He takes a water-pot and a handful of Darbha grass, goes forth, his face turned towards the east, spreads the Darbha grass out with its points towards the east, and makes four Bali-offerings on that (grass) with (the formulas), 'To the terrestrial Serpents I offer this Bali,' 'To the aerial, &c.; to the celestial, &c.; to the Serpents dwelling in the quarters (of the world),' &c.