Anandakanda 1.9.38

1.9.38

taptakhalve vajramūṣāgataṃ kṛtvā nirodhayet /
pacedbhūdharayantre ca punarādāya taṃ rasam //

Having placed it into a diamond crucible in a heated mortar, one should seal it,
and cook it in a bhūdhara-yantra; then, taking that mercury out again,