YV 3.6h

He puts (it) up to the east (of the fire), for before the sacrifice it is proclaimed, for what is not proclaimed is that of which when it is passed men say, 'This should have been done.' The Sadhya gods despised the sacrifice; the sacrifice touched them not; what was superabundant in the sacrifice touched them. The superabundant part of the sacrifice is the producing of fire and casting it on the fire; the superabundant part [8] of the post is the part above the top; that is their share; verily by it he delights them. The gods when the Soma sacrifice was complete cast the offering-spoons (into the fire) and the post; they reflected, 'Here we are making a disturbance of the sacrifice', they saw a ransom in the bunch of grass for the offering-spoons, in the chip for the post. When the Soma sacrifice is complete he casts (in the fire) the bunch of grass, he offers the chip, to avoid disturbing the sacrifice. The Sadhya gods were in this world and nothing else living. They offered Agni as a sacrifice to Agni, for they found nothing else to offer; thence indeed these creatures were born; in that he casts the fire on the fire after producing it, (it serves for) the propagation of offspring. Now the fire is Rudra, the beast the sacrificer; if he were to produce the fire after offering the beast, he would place the sacrificer in the power of Rudra [1], and he would be liable to die. Or rather they say, 'All the gods are the fire, the beast the offering'. In that he produces the fire after offering the beast, he brings forth all the gods for the offering which is made ready. The fire should be produced, after bringing up (the beast). The offering is then neither finished nor not begun. 'Thou art the birthplace of Agni', he says, for that is the birthplace of Agni. 'Ye are the two male ones', he says, for they are the two male ones [2]. 'Thou art Urvaçi, thou art Ayu', he says, to make a pair.