Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 34: Satyavatī, Viśvāmitra’s Elder Sister
Text 1.34.6

स पिता मम काकुत्स्थ गाधिः परमधार्मिकः
कुशवंशप्रसूतोऽस्मि कौशिको रघुनन्दन

sa pitā mama kākutstha gādhiḥ parama-dhārmikaḥ
kuśa-vaṁśa-prasūto
’smi kauśiko raghu-nandana

saḥ = that; pitā = was father; mama = my; kākutstha = O descendant of Kakutstha; gādhiḥ = Gādhi; parama-dhārmikaḥ = greatly dhārmika; kuśa-vaṁśa-prasūtaḥ asmi kauśikaḥ = therefore I am Kauśika born in the dynasty of Kuśa; raghu-nandana = and beloved child of the Raghus.

O descendant of Kākutstha and beloved child of the Raghus, that greatly dhārmika Gādhi was my father. Therefore, I am Kauśika, born in the dynasty of Kuśa.

Viśvāmitra was named Kauśika, one who had taken birth in the dynasty of Kuśa.