Njanappana is a popular prayer dedicated to Sri Krishna, to the Guruvayurappan form of Krishna worshipped in Sri Krishna Temple in Guruvayur. This particular Njanappana Lyrics in Malayalam is in pdf format.
Njanappana was written by Poonthanam in the 16th century and contains simple worldly wisdom in Malayalam.
Link - Njanappana Lyrics in Malayalam in pdf