SB 6.6.40

vivasvataḥ śrāddhadevaṁ
 saṁjñāsūyata vai manum
mithunaṁ ca mahā-bhāgā
 yamaṁ devaṁ yamīṁ tathā
saiva bhūtvātha vaḍavā
 nāsatyau suṣuve bhuvi
Synonyms: 
vivasvataḥ — of the sun-god; śrāddhadevam — named Śrāddhadeva; saṁjñā — Saṁjñā; asūyata — gave birth; vai — indeed; manum — to Manu; mithunam — twins; ca — and; mahā-bhāgā — the fortunate Saṁjñā; yamam — to Yamarāja; devam — the demigod; yamīm — to his sister named Yamī; tathā — as well as; — she; eva — also; bhūtvā — becoming; atha — then; vaḍavā — a mare; nāsatyau — to the Aśvinī-kumāras; suṣuve — gave birth; bhuvi — on this earth.
Translation: 
Saṁjñā, the wife of Vivasvān, the sun-god, gave birth to the Manu named Śrāddhadeva, and the same fortunate wife also gave birth to the twins Yamarāja and the river Yamunā. Then Yamī, while wandering on the earth in the form of a mare, gave birth to the Aśvinī-kumāras.