Rasarnava 8.23

8.23

saṃkarākhyaṃ tu durmelyaṃ priye mṛdukharāhvayam
tataḥ saṃmṛditaṃ devi dvaṃdvamelāpanaṃ drutam
bhavet samarasaṃ garbhe rasarājasya ca dravet //

That which is called composite, difficult to unite, O beloved, designated soft and hard— / then ground, O goddess, the combination of pairs is liquefied; / it becomes homogeneous in the interior, and liquefies into the king of mercury.