Śatapatha Brāhmaṇa ("of a hundred paths") 2.6.1.41

2.6.1.41

athodapātramādāya | punaḥ prasalavi triḥ pariṣiñcanparyeti sa yajamānasya pitaramavanejayatyasāvavanenikṣvetyasāvavanenikṣveti pitāmahamasāvavanenikṣveti prapitāmahaṃ tadyathā jakṣuṣe 'bhiṣiñcedevaṃ tattadyatpunaḥ prasalavi triḥ pariṣiñcanparyeti prasalavi na idaṃ karmānusaṃtiṣṭhātā iti tasmātpunaḥ prasalavi triḥ pariṣiñcanparyeti

He now takes the vessel of water and again, while sprinkling, walks thrice round (the altar) from left to right (sunwise). With 'N.N., wash thyself!' he pours out water (in the respective corner) for the Sacrificer's father to wash himself; with 'N.N., wash thyself!' for the grandfather; with 'N.N., wash thyself!' for the great-grandfather. As one would pour out water for (a guest) who has taken food with him, so in this case. And as to his again walking thrice round from left to right, while sprinkling,--they think, 'This holy work of ours shall be accomplished sunwise,' and hence he walks thrice round from left to right, while sprinkling.