Matsyapurana 25.57

25.57

*śaunaka uvāca
guroḥ sakāśātsamavāpya vidyāṃ bhittvā kukṣiṃ nirvicakrāma vipraḥ
prāleyādreḥ śuklamudbhidya śṛṅgaṃ rātryāgame paurṇamāsyāmivenduḥ //

Śaunaka said that the Brâhmaṇa then acquired that knowledge from his preceptor, and, after opening the stomach of Śukra, emerged from it as does the full moon at the approach of night by bursting open through the eastern horizon.—57.