Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 39
Sanskrit:
सा वै सप्त समा गर्भमबिभ्रन्न व्यजायत ।जघ्नेऽश्मनोदरं तस्या: सोऽश्मकस्तेन कथ्यते ॥ ३९ ॥
ITRANS:
sā vai sapta samā garbhamabibhran na vyajāyatajaghne ’śmanodaraṁ tasyāḥso ’śmakas tena kathyate
Translation:
Madayantī bore the child within the womb for seven years and did not give birth. Therefore Vasiṣṭha struck her abdomen with a stone, and then the child was born. Consequently, the child was known as Aśmaka [“the child born of a stone”].