Atharvavedaparishishta 70.4.3

70.4.3

divyādbhuteṣu kartavyaḥ koṭihomasamanvitaiḥ | gosahasraṃ ca dātavyaṃ gurave dakṣiṇāvidhiḥ ||

For celestial portents, [the rite] is to be performed by those endowed with ten million oblations; / and a thousand cows are to be given to the guru: this is the rule of the sacrificial fee.