Anandakanda 1.5.2

1.5.2

śrībhairavaḥ /
śṛṇu devi vakṣyāmi bhūcarākhyaṃ tu jāraṇam /
<bhūcarī jāraṇā>
kṛṣṇaṃ pītaṃ tathā raktaṃ śulbe tīkṣṇe ca melayet //

Glorious Bhairava [said]:
Listen, O goddess, I shall explain the digestion named 'earth-roaming.'
<The Earth-Roaming Digestion>
One should mix black, yellow, and red [substances] into copper and wrought iron.