Although Yuvanāśva went into the forest with his one hundred wives, all of them were very morose. The sages in the forest, however, being very kind to the King, began very carefully and attentively performing an Indra-yajña so that the King might have a son.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
भार्याशतेन निर्विण्ण ऋषयोऽस्य कृपालवः । इष्टिं स्म वर्तयाञ्चक्रुरैन्द्रीं ते सुसमाहिताः
bhāryāśatena nirviṇṇa ṛṣayo'sya kṛpālavaḥ | iṣṭiṃ sma vartayāñcakruraindrīṃ te susamāhitāḥ
SB 9.6.26