YV 4.5c

If he were to offer with the milk of domesticated animals [1], he would afflict domestic animals with pain; if (with that) of wild (animals), wild (animals); he should offer with groats of wild sesame or with groats of Gavidhuka grass; he harms neither domesticated nor wild animals. Then they say, 'Wild sesame and Gavidhuka grass are not a proper offering'; he offers with goat's milk, the female goat is connected with Agni; verily he offers with a proper offering; he harms neither domesticated nor wild animals. The Angirases going to the world of heaven [2] spilled the cauldron on the goat; she in pain dropped a feather (like hair), it became the Arka (plant); that is why the Arka has its name. He offers with a leaf of the Arka, to unite it with its birthplace. He offers standing facing north; this is the quarter of Rudra; verily he propitiates him in his own quarter. He offers on the last brick; verily at the end he propitiates Rudra. He offers dividing it into three; these worlds are three; verily he makes these worlds of even strength; at this height he offers [3], then at this, then at this; these worlds are three; verily he appeases him for these worlds. Three further libations he offers; they make up six, the seasons are six; verily with the seasons he appeases him. If he were to offer while wandering round, he would make Rudra come within (the sacrifice). Or rather they say, 'In what quarter is Rudra or in what?' He should offer them while wandering round; verily he appeases him completely [4].