Aitareya-Aranyaka: Second Aranyaka, Third Adhyâya, Fourth Khanda
1. He who knows one sacrifice above another, one day above another, one deity above the others, he is clever. Now this great uktha (the nishke-valya-sastra) is the sacrifice above another, the day above another, the deity above others.
2. This uktha is fivefold. With regard to its being performed as a Stoma (chorus), it is Trivrit, Pahkadasa, Saptadasa, Ekavimsa, and Pankavimsa. With regard to its being performed as a Siman (song), it is Gayatra, Rathantara, Brihat, Bhadra, and Ragana. With regard to metre, it is Gâyatrî, Ushnih, Brihatî, Trishtubh, and Dvipadi. And the explanation (given before in the Aranyaka) is that it is the head, the right wing, the left wing, the tail, and the body of the bird.
3. He performs the Prastava in five ways, he performs the Udgitha in five ways, he performs the Pratihara in five ways, he performs the Upadrava in five ways, he performs the Nidhana in five ways. All this together forms one thousand Stobhas, or musical syllables.
4. Thus also are the Rik verses, contained in the Nishkevalya, recited (by the Hotri) in five orders. What precedes the eighty trikas, that is one order, then follow the three sets of eighty trikas each, and what comes after is the fifth order.
5. This (the hymns of this Sastra) as a whole (if properly counted with the Stobha syllables) comes to one thousand (of Brihatî verses). That (thousand) is the whole, and ten, ten is called the whole. For number is such (measured by ten). Ten tens are a hundred, ten hundreds are a thousand, and that is the whole. These are the three metres (the tens, pervading everything). And this food also (the three sets of hymns being represented as food) is threefold, eating, drinking, and chewing. He obtains that food by those (three numbers, ten, hundred, and thousand, or by the three sets of eighty trikas).