Skandapurana 1.4.11.155

1.4.11.155

dhanvaṃtarirgomayaṃ ca sarvalokeśvareśvaram..
gaṃdharvā dārujaṃ liṃgaṃ sarvaśreṣṭheti nāma ca.. 13.155 ..

Dhanvantari, a cow-dung [liṅga], [reciting the name] “Lord of Lords of All the Worlds”;
the Gandharvas, a wooden liṅga, and the name “Foremost of All”;