Śatapatha Brāhmaṇa ("of a hundred paths") 1.3.5

With the fire-wood (idhma, lighting material) the Adhvaryu lights (indh) the fire: hence it is called fire-wood. And with the kindling verses (sâmidhenî) the Hotri kindles (sam-indh, to make blaze): hence they are called kindling verses.

He (the Adhvaryu) says (to the Hotri): 'Recite to the fire as it is being kindled!' for it is to the fire, when it is being kindled, that he recites.

Here now some people say, 'O Hotar, recite to the fire as it is being kindled!' But let him not say so; for that (priest) is not a Hotri as yet; only when he (the sacrificer) elects him, does he become a Hotri. Let him therefore say, 'Recite to the fire as it is being kindled!'

He recites (verses) addressed to Agni: he accordingly kindles it (the fire) with the aid of its own deity. In the gâyatrî metre (are the verses which) he recites; for the gâyatrî is Agni's metre: by means of its own metre he thereby kindles it. The gâyatrî is vigour, the gâyatrî is the brahman (the priestly order): with vigour he thereby kindles it.

Eleven (verses) he recites; for of eleven syllables consists the trishtubh metre. The gâyatrî is the brahman and the trishtubh is the kshatra (or military order). With the aid of these two energies he thus kindles it: for this reason he recites eleven (verses).

Thrice he recites the first verse, and thrice the last one; for of threefold beginning are sacrifices, and of threefold termination: therefore he recites thrice the first and the last (verses).

Fifteen sâmidhenî verses result (from this repetition of the first and last of the eleven verses). The fifteen-versed chant, doubtless, is the thunderbolt, and the thunderbolt means strength; so that he thereby converts the sâmidhenîs into strength: hence, if he should hate any one, he may crush him with his great toes at the time when those (verses) are recited. By saying, 'I here crush so and so!' he crushes him with that thunderbolt.

Fifteen nights indeed there are in a half-moon; and growing by half-moons the year passes: hence he thereby obtains the nights.

Now in the fifteen gâyatrî verses there are indeed three hundred and sixty syllables; and three hundred and sixty days there are in a year: hence he thereby obtains the days, he thereby obtains the year.

For an ishti (which is performed in order to obtain the fulfilment of a special wish) let him recite seventeen sâmidhenî verses; for in a low voice he sacrifices to the deity to which he offers an ishti. Twelve months, namely, there are in a year, and five seasons: this (makes) the seventeenfold Pragâpati. For verily Pragâpati is all: hence for what wish he performs the ishti, that wish he thus accomplishes by means of the All. In a low voice he sacrifices to the deity; for what is spoken in a low voice is undefined (indistinct), and undefined is the 'All:' hence for whatever wish he performs the ishti, that wish he thus accomplishes by means of the All. This is the practice in regard to an ishti.

Some people say: 'Let him recite twenty-one sâmidhenî verses also at the full- and new-moon sacrifice.' Twelve, doubtless, are the months of the year, five the seasons, and three these worlds: this (makes) twenty; and the twenty-first is this very (sun) that here shines: he is the resort, he the stay; thereby he (the sacrificer) obtains this resort, this stay. He may therefore recite twenty-one.

Let him recite them only for one of established prosperity (gatasrî), who would not wish to become either better or worse. For, what he for whom they recite is like, like that he will either be or worse, for whom, that knows this, they recite those (twenty-one verses). This, however, is mere speculation, for those (twenty-one verses) are not recited.

Thrice he should recite the first and thrice the last (verse), without drawing breath; for three are these worlds, so that he thereby spreads (san-tan) these worlds, gains these worlds. Also three breaths there are in man: this recitation thereby causes him (the sacrificer) to be extended (santata), not cut short (by death).

He (the Hotri) should endeavour to recite this (uninterruptedly) as long as his strength lasts. If, on the other hand, he were to take breath in the middle (of the verse), it would be a slight on this very (sacrifice): by reciting this (holy) composition without taking breath, that slight will be avoided.

If, however, he do not care to undertake this, he may also recite one (verse) at a time without drawing breath: he thereby spreads those worlds one by one, gains those worlds one by one. The reason why he takes breath, is that the gâyatrî is indeed breath; and that by reciting a complete gâyatrî verse, he accordingly bestows complete breathing (on the sacrificer): let him therefore recite one (verse) at a time without breathing.

He recites them in a continuous, uninterrupted way: thereby he makes the days and nights of the year continuous, and in a continuous, uninterrupted way revolve those days and nights of the year. And in this way he gives no access to the spiteful enemy; but access he would indeed give, if he were to recite them discontinuously: he therefore recites in a continuous, uninterrupted way.