Skandapurana 5.29.54

5.29.54

atha vīrudhasaṃchanne vane tasminsusaṃsthite ..
tayā nyastaṃ padaṃ mūrdhni tṛṇācchannasya bhoginaḥ .. 54 ..

Now, in that forest densely covered with creepers and well established,
her foot was placed upon the head of a serpent concealed by grass.