The Concise Oxford Dictionary of World Religions (1922 page)

a's and R
dh
's love-making in terms of the secular poetic conventions, later mystics and religious movements have treated it as a religious, mystical work.
A second factor in the evolution of R
dh
as central religious figure was evidently the teaching of the theologian
Nimb
rka
(14th/15th cent.?). By him K
a is regarded as identical with
Brahman
, and R
dh
as co-natural with him. Similar ideas are expressed by many subsequent theologies.
The poetry about K
a's love for R