Gobhilagrihyasutra 1.4.9

1.4.9

- athā 'parān balīn hared udadhānasya madhyamasya dvārasyā: 'bdaivataḥ prathamo balir bhavaty, oṣadhivanaspatibhyo dvitīya, ākāśāya tṛtīyaḥ.

Then he should offer other Balis (near) the water-pot, the middle (post, and) the door: the first Bali is sacred to the Waters, the second to the Herbs and Trees, the third to the Ether.