Śrīmad-Bhāgavatam · Text 3.21.5
Who is speaking and story frame
रुचिर्यो भगवान् ब्रह्मन्दक्षो वा ब्रह्मण: सुत: ।
यथा ससर्ज भूतानि लब्ध्वा भार्यां च मानवीम् ॥ ५ ॥
rucir yo bhagavān brahman
dakṣo vā brahmaṇaḥ sutaḥ
yathā sasarja bhūtāni
labdhvā bhāryāṁ ca mānavīm
O holy sage, tell me how the worshipful Ruci and Dakṣa, the son of Brahmā, generated children after securing as their wives the other two daughters of Svāyambhuva Manu.
Read Śrīla Prabhupāda's purport on Vedabase.io