Aitareyabrahmana 3.2.p22

3.2.p22

iii. 21 (xii. 10) Indra, having slain Vṛtra, having won all victories, said to Prajāpati ‘Let me be what thou art; let me be great.’ Prajāpati replied, ‘Then who am I?’ ‘Even that which thou hast said’ he answered; then indeed did Prajāpati become Who by name; Prajāpati is Who by name. In that Indra became great, that is why Mahendra has his name. He having become great said to the deities ‘Assign me a choice portion’, just as one desires here, who prospers, who attains pre-eminence, who becomes great. The gods said to him ‘Claim thyself what is to be for thee.’ He claimed this cup for Mahendra, the midday of pressings, the Niṣkevalya of litanies, the Triṣṭubh of metres, the Pṛṣṭha of Sāmans; this choice portion they assigned to him. They assign a choice portion to him who knows thus. To him the gods said ‘All hast thou asked; let us have a share here also.’ ‘No’, he replied, ‘how can you have a share also?’ They answered ‘Let us have a share also, O bounteous one.’ He merely looked at them.