The Concise Oxford Dictionary of World Religions (1883 page)

relates humans to the domain and action of the deities in all their many ways of sustaining or threatening the cosmos and life within it, and thus it takes a vast number of different ritual forms, of which the simplest is
dar
an
, looking on the image of the deity (or in the case of Jains, on the image of a
t
rtha
kara
; among the Jains, an ascetic can only look at an image, never act toward it; such interior devotion is known as
caityavandana
, and is one of the six obligations). P
j
is mentioned in the early
G
hya S
tras
, with focus on home rituals (which remain central). In the
S
tras
, the reception of, and hospitality for,
brahmans
in the home to preside over rites for ancestors is called p
j
, and it may be that
devap
j
(worship of deities) developed from this:
devap
j