Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 37
Sanskrit:
एवं कौशिकगोत्रं तु विश्वामित्रै: पृथग्विधम् ।प्रवरान्तरमापन्नं तद्धि चैवं प्रकल्पितम् ॥ ३७ ॥
ITRANS:
evaṁ kauśika-gotraṁ tuviśvāmitraiḥ pṛthag-vidhampravarāntaram āpannaṁtad dhi caivaṁ prakalpitam
Translation:
Viśvāmitra cursed some of his sons and blessed the others, and he also adopted a son. Thus there were varieties in the Kauśika dynasty, but among all the sons, Devarāta was considered the eldest.