Visvamitra accepted the son of Ajigarta known as Sunahsepha, who was born in the Bhrgu dynasty and was also known as Devarata, as one of his own sons. Visvamitra ordered his other sons to accept Sunahsepha as their eldest brother

Expressions researched:
"Viśvāmitra accepted the son of Ajīgarta known as Śunaḥśepha, who was born in the Bhṛgu dynasty and was also known as Devarāta, as one of his own sons. Viśvāmitra ordered his other sons to accept Śunaḥśepha as their eldest brother"

Srimad-Bhagavatam

SB Canto 9

Viśvāmitra accepted the son of Ajīgarta known as Śunaḥśepha, who was born in the Bhṛgu dynasty and was also known as Devarāta, as one of his own sons. Viśvāmitra ordered his other sons to accept Śunaḥśepha as their eldest brother.

SB 9.16.30, Translation

Viśvāmitra accepted the son of Ajīgarta known as Śunaḥśepha, who was born in the Bhṛgu dynasty and was also known as Devarāta, as one of his own sons. Viśvāmitra ordered his other sons to accept Śunaḥśepha as their eldest brother.