Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 47: King Sumati Approaches Viśvāmitra
Text 1.47.16

सोमदत्तस्य पुत्रस्तु काकुत्स्थ इति विश्रुतः॥

somadattasya putras tu kākutstha iti viśrutaḥ

somadattasya putraḥ tu = Somadatta’s son; kākutstha iti viśrutaḥ = Kākutstha is famous as.

Somadatta’s son is famous as Kākutstha.