We all know famous duet filmed on Mehmood and Kishore Kumar. However, it was originally sung by Ashok Kumar for movie Jhoola (1941). Song was written by Pradeep and music was by Sarswati Devi.
Kishore Kumar suggested this song of his older brother to lyricist Rajinder Krishan to write extension for Padosan.

MOVIE: Jhoola 1941,
SINGER: Ashok Kumar,
LYRCIS: Pradeep,
MUSIC: Saraswati Devi