Matsyapurana 51.15

51.15

tāsu ṣoḍaśadhātmānaṃ pravibhajya pṛthakpṛthak
tadā tu viharaṃstāsu dhiṣṇyecchaḥ sa babhūva ha //

After dividing his body into sixteen different parts, he dallied with these sixteen river-goddesses, when he was attracted towards Dhiṣṇyas. Produced from these Dhiṣṇyas was the progeny known as Dhiṣṇus. Since they were the sons of Dhiṣṇyas, they are called Dhiṣṇus.—13-16.