Agniveshyagrihyasutra 2.5.11

Now we shall explain the offering to beings.

One desiring rain is eligible [to perform it]. A black garment, a black cow, a black ewe, black rice, black honey, an unbaked jar, date-meal, ghee, and three lotus leaves—these ritual requisites are prepared for him.

"When one offers a tribute to beings, then the sacrifice to beings is concluded"—thus says the Brāhmaṇa.

Year after year, every six months, when it is dry on the new-moon day, or when he observes an obstruction to rain, then he should offer the offering to beings.

Having gone to a pond, on a clean spot, having dug up [the ground] with "Being dug up...", having sprinkled it with "May the divine [waters] be for our welfare...", having taken possession of the place of sacrifice to the gods, he draws lines around it with "Encompassed by lines...".

At the time when a west wind blows, at that time the Brahmin, having put on the black garment with "You belong to the Maruts, the strength of the Maruts," having touched water, put on the sacred thread, sipped water, and taken a vessel of water, establishes the being behind [the fire] and worships it.

Having performed [the rites] up to the mystic utterances, he offers [oblations with] the eight names of the wind: "To the east wind, raining, quickening, enveloping, svāhā!"

Then he offers boiled rice portions of black rice [with]: "To Mitra and Varuṇa, svāhā! To Agni, coverer of dwelling, svāhā! To the Maruts, svāhā! To Sūrya, svāhā! To Agni Sviṣṭakṛt, svāhā!"

Having offered [the oblations] beginning with the one to Varuṇa and ending with the one to Sviṣṭakṛt, then, having cut off portions of the remaining food and date-meal into a bronze vessel or an earthenware bowl, he mixes them with ghee or honey,

with the two [formulas beginning with] "Tardy, roaring...".

To the west of the fire, on three lotus leaves, he should apportion [it], with: "O divine Vasus..."

With three [formulas], he offers half of the remainder of the food, with: "At the impulse of the divine Savitṛ..."

Then, having gone to the water, he casts three balls of the remainder into the water-drops,

with three [formulas] ending with svāhākāra: "Give water! Split the ocean!"

Then, having taken up water with his folded hands, he should toss it up, with the two [verses]: "Send forth, O Maruts..."

Then, having gone to the deity of the dwelling:

"Those who are the deities of the dwelling, and those who are the hordes of fierce demons and spirits,

to them I, desiring rain, bring an offering. May they, being pacified, produce peace!"

With: "Homage to all! Homage to the spirits! Homage...", and having filled an unbaked jar with water, and [looking at] a black cow, with: "Make the earth rise up..."

Then he waits upon the deities with: "Whatever gods have their share in the sky..."

He waits upon the rain clouds with: "May the rivers flow! May the clouds rain!" Having made [Brahmins] declare an auspicious day and having fed Brahmins,

if it should rain, one should only offer so much; if it does not rain, on the next day he should apportion the oblation. Such is the brāhmaṇa passage.