Śatapatha Brāhmaṇa ("of a hundred paths") 1.2.4.2

1.2.4.2

tato dvābhyām brāhmaṇā yajñe caranti dvābhyāṃ rājanyabandhavaḥ saṃvyādhe yūpena ca sphyena ca brāhmaṇā rathena ca śareṇa ca rājanyabandhavaḥ

In consequence of this, the priests make use of two (of these pieces) at the sacrifice, and men of the military caste (râganyabandhu) also make use of two of them in battle: viz. the priests make use of the sacrificial post and the wooden sword, and the men of the military caste of the chariot and the arrow.