Matsya Purana — Paurava Genealogy: Bharata
यदा स यजमानस्तु पुत्रं नासादयत्प्रभुः ततः क्रतुं मरुत्सोमं पुत्रार्थे समुपाहरत् //
yadā sa yajamānastu putraṃ nāsādayatprabhuḥ tataḥ kratuṃ marutsomaṃ putrārthe samupāharat //
When that eminent sacrificer did not obtain a son, he then undertook the Marutsoma kratu, performing it with the aim of begetting a putra (son).
This verse does not describe pralaya; it focuses on a pragmatic dharmic response—undertaking a specific Soma-rite (Marutsoma) to obtain progeny and sustain lineage.
It frames progeny as a legitimate household aim (putrārtha) and presents Vedic sacrifice as a sanctioned means for a yajamāna—whether a king or householder—to pursue lineage-continuity within dharma.
The significance is ritual: it names the Marutsoma kratu, a Soma-sacrifice, indicating that specific, named rites were prescribed for specific aims (here, begetting a son).