In that great human sacrifice, Viśvāmitra was the chief priest to offer oblations, the perfectly self-realized Jamadagni had the responsibility for chanting the mantras from the Yajur Veda, Vasiṣṭha was the chief brahminical priest, and the sage Ayāsya was the reciter of the hymns of the Sāma Veda.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
मुक्तोदरोऽयजद्देवान् वरुणादीन् महत्कथः । विश्वामित्रोऽभवत्तस्मिन् होता चाध्वर्युरात्मवान्
muktodaro'yajaddevān varuṇādīn mahatkathaḥ | viśvāmitro'bhavattasmin hotā cādhvaryurātmavān
SB 9.7.22