Even as the soft fibres of the ishika reed, when thrown into fire, are burnt, so also are burnt all the sins of one who, knowing this, offers an Agnihotra oblation.
Sama Veda, Chandogya Upanishad V, XXIV – The Glory of the Agnihotra Sacrifice, 3
Therefore even if a man who knows this gives what is left of his food to a chandala, he verily offers it to his Vaisvanara Self. On this there is the following verse:
Sama Veda, Chandogya Upanishad V, XXIV – The Glory of the Agnihotra Sacrifice, 4
It was this same ritual the Seers, our Fathers, adopted when in the beginning sacrifice was first created. With the eyes of my mind I believe I can envisage those who were first to offer this sacrifice.
Rig Veda X, 130, 6
The rituals, meters, and hymns were according to the rubrics, even those of the Seven godlike Seers of old. When the sages follow in the path traced by the ancestors they take the reins in their hands like charioteers.
Rig Veda X, 130, 7
To the Lord, the far-renowned, the wise Ordainer, ancient and glorious, I offer the tribute of a song. Anointed with oil is he, the Lord, the powerful giver of bliss and guardian of noble riches.
Rig Veda V, 15, 1