Śatapatha Brāhmaṇa ("of a hundred paths") 11.5.6

There are five great sacrifices, and they, indeed, are great sacrificial sessions,--to wit, the sacrifice to beings, the sacrifice to men, the sacrifice to the Fathers, the sacrifice to the gods, and the sacrifice to the Brahman.

Day by day one should offer an oblation to beings: thus he performs that sacrifice to beings. Day by day one should offer (presents to guests) up to the cupful of water: thus he performs that sacrifice to men. Day by day one should offer with Svadhâ up to the cupful of water: thus he performs that sacrifice to the Fathers. Day by day one should perform with Svâhâ up to the log of firewood: thus he performs that sacrifice to the gods.

Then as to the sacrifice to the Brahman. The sacrifice to the Brahman is one's own (daily) study (of the Veda). The guhû-spoon of this same sacrifice to the Brahman is speech, its upabhrit the mind, its dhruvâ the eye, its sruva mental power, its purificatory bath truth, its conclusion heaven. And, verily, however great the world he gains by giving away (to the priests) this earth replete with wealth, thrice that and more--an imperishable world does he gain, whosoever, knowing this, studies day by day his lesson (of the Veda): therefore let him study his daily lesson.

Verily, the Rik-texts are milk-offerings to the gods; and whosoever, knowing this, studies day by day the Rik-texts for his lesson, thereby satisfies the gods with milk-offerings; and, being satisfied, they satisfy him by (granting him) security of possession, by life-breath, by seed, by his whole self, and by all auspicious blessings; and rivers of ghee and rivers of honey flow for his (departed) Fathers, as their accustomed draughts.

And, verily, the Yagus-texts are ghee-offerings to the gods; and whosoever, knowing this, studies day by day the Yagus-texts for his lesson thereby satisfies the gods with ghee-offerings; and, being satisfied, they satisfy him by security of possession, by life-breath, by seed, by his whole self, and by all auspicious blessings; and rivers of ghee and rivers of honey flow for his Fathers, as their accustomed draughts.

And, verily, the Sâman-texts are Soma-offerings to the gods; and whosoever, knowing this, studies day by day the Sâman-texts for his lesson thereby satisfies the gods with Soma-offerings; and, being satisfied, they satisfy him by security of possession, by life-breath, by seed, by his whole self, and by all auspicious blessings; and rivers of ghee and rivers of honey flow for his Fathers, as their accustomed draughts.

And, verily, the (texts of the) Atharvâṅgiras are fat-offerings to the gods; and whosoever, knowing this, studies day by day the (texts of the) Atharvâṅgiras for his lesson, satisfies the gods with fat-offerings; and, being satisfied, they satisfy him by security of possession, by life-breath, by seed, by his whole self, and by all auspicious blessings; and rivers of ghee and rivers of honey flow for his Fathers, as their accustomed draughts.

And, verily, the precepts, the sciences, the dialogue, the traditional myths and legends, and the Nârâsamsî Gâthâs are honey-offerings to the gods; and whosoever, knowing this, studies day by day the precepts, the sciences, the dialogue, the traditional myths and legends, and the Nârâsamsî Gâthâs, for his lesson, satisfies the gods with honey-offerings; and, being satisfied, they satisfy him by (granting him) security of possession, by life-breath, by seed, by his whole self, and by all auspicious blessings; and rivers of ghee and rivers of honey flow for his Fathers, as their accustomed draughts.

Now, for this, sacrifice to the Brahman there are four Vashat-calls,--to wit, when the wind blows, when it lightens, when it thunders, and when it rumbles whence he who knows this should certainly study when the wind is blowing, and when it lightens, or thunders, or rumbles, so as not to lose his Vashat-calls; and verily he is freed from recurring death, and attains to community of nature (or, being) with the Brahman. And should he be altogether unable (to study), let him at least read a single divine word; and thus he is not shut out from beings.