Vishnupurana 1.12.5

1.12.5

yatra vai devadevasya sānnidhyaṃ harimedhasaḥ /
sarvapāpahare tasmiṃstapastīrthe cakāra saḥ //

THE prince, having received these instructions, respectfully saluted the sages, and departed from the forest, fully confiding in the accomplishment of his purposes. He repaired to the holy place, on the banks of the Yamuná, called Madhu or Madhuvana, the grove of Madhu, after the demon of that name, who formerly abided there. Śatrughna (the younger brother of Ráma) having slain the Rákshas Lavańa, the son of Madhu, founded a city on the spot, which was named Mathurá. At this holy shrine, the purifier from all sin, which enjoyed the presence of the sanctifying god of gods, Dhruva performed penance, as enjoined by Maríchi and the sages: he contemplated Vishńu, the sovereign of all the gods, seated in himself. Whilst his mind was wholly absorbed in meditation, the mighty Hari, identical with all beings and with all natures, (took possession of his heart.) Vishńu being thus present in his mind, the earth, the supporter of elemental life, could not sustain the weight of the ascetic. As he stood upon his left foot, one hemisphere bent beneath him; and when he stood upon his right, the other half of the earth sank down. When he touched the earth with his toes, it shook with all its mountains, and the rivers and the seas were troubled, and the gods partook of the universal agitation.