Anandakanda 1.4.159

1.4.159

gandhābhrayoganiṣke dve piṣṭaṃ kuryādyathā tathā /
taṃ piṣṭaṃ nāgapiṣṭyātha samayā pariveṣṭayet //

[and] two niṣkas of the sulfur-mica combination should be ground in whatever manner [needed] to form a paste. / Then one should encase that paste with an equal amount of lead paste;