The Skanda Upanishad ends with the hymn:[REF] And the highest step of Vishnu The patrons see for ever Like an eye, stationed in heaven.
This hymn originates from the Rig Veda and appears in other Upanishadic texts like Aruneya Upanishad, Nrisimha Tapaniya Upanishad, Vasudeva Upanishad and Muktika Upanishad [REF].