Bhagavatapurana 9.11.14

9.11.14

tadīyaṃ dhanamānīya sarvaṃ rājñe nyavedayat /
śatrughnaśca madhoḥ putraṃ lavaṇaṃ nāma rākṣasam /
hatvā madhuvane cakre mathurāṃ nāma vai purīm //

14. He brought all their wealth and offered it to the king; Satrughna vanquished a Rakshasa called Lavana, son of Madhu, and in the forest of Madhu he caused a city to be built called Mathura (D. converted Madhuvana into the city of Madhura).