Matsyapurana 93.105

93.105

athavā ṛtvijau śāntau dvāveva śrutikovidau
kāryāvayutahome tu na prasajyeta vistare //

The Dakṣiṇâ to the sacrificial priests should be given free from anger and bias, and with a calm mind. There should be four Brâhmaṇas, well-versed in the Vedas, to officiate on the occasion of the sacrifice of the Nine Planets, or only two such Brâhmaṇas, of peaceful disposition and versed in the Vedas, should be made officiating priests. This is in case of the sacrifice of ten thousand Homa offerings. The number of Brâhmaṇas need not be greater than those mentioned above.—104-105.