Skandapurana 1.4.11.146

1.4.11.146

sanakādyaiśca talliṃgaṃ pūjyājayurjagadgatim..
darbhāṃkuramayaṃ sapta munayo viśvayonikam.. 13.146 ..

and Sanaka and the others, worshipping that liṅga, attained the goal of the world.
The seven seers [worshipped a liṅga] made of sprouted Darbha grass, [reciting the name] “Womb of the Universe”;