Shatapatha Brahmana 11.1.6.2

11.1.6.2

tataḥ saṃvatsare puruṣaḥ samabhavat sa prajāpatistasmādu saṃvatsara eva strī vā gaurvā vaḍabā vā vijāyate saṃvatsare hi prajāpatirajāyata sa idaṃ hiraṇmayamāṇḍaṃ vyarujannāha tarhi kā cana pratiṣṭhāsa tadenamidameva hiraṇmayamāṇḍaṃ yāvatsaṃvatsarasya velāsīttāvadbibhratparyaplavata

In a year's time a man, this Pragâpati, was produced therefrom; and hence a woman, a cow, or a mare brings forth within the space of a year; for Pragâpati was born in a year. He broke open this golden egg. There was then, indeed, no resting-place: only this golden egg, bearing him, floated about for as long as the space of a year.