Rathītara had no sons, and therefore he requested the great sage Aṅgirā to beget sons for him. Because of this request, Aṅgirā begot sons in the womb of Rathītara’s wife. All these sons were born with brahminical prowess.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
रथीतरस्याप्रजस्य भार्यायां तन्तवेऽर्थितः । अङ्गिरा जनयामास ब्रह्मवर्चस्विनः सुतान्
rathītarasyāprajasya bhāryāyāṃ tantave'rthitaḥ | aṅgirā janayāmāsa brahmavarcasvinaḥ sutān
SB 9.6.2