Anandakanda 1.2.72

1.2.72

namaḥ śaktiriti khyātaṃ rahasyaṃ mantramuttamam /
<rasaliṅgārcanā>
rasaliṅgārcanaṃ vakṣye bhairavi śṛṇu tattvataḥ //

and namaḥ is proclaimed as the power—this is the excellent, secret mantra.
<Worship of the Mercury Liṅga>
I shall declare the worship of the mercury liṅga; hear it in truth, O Bhairavī.