In Yatindra Mata Dipika I came across the section where pramana and prameya where being explained. Dharmabhutajnana is said to be common to both cit and Isvara. I don't understand what that is supposed to convey.Is Dharmabhutajnana the building block of both Isvara and cit,if so why is cit said to be part of Isvara?
Firstly, I am pleasantly surprised to see the rare mention of the book Yatindramatadipika (यतीन्द्रमतदीपिका). It is a very good, well-written prose that is easy to understand. Just to give a brief intro about the book itself, it literally means "the light on the system of philosophy of Yatindra i.e. Ramanuja".
Dharmabhutajnanam (धर्मभूतज्ञानम्) is categorized in the Yatindramatadipika as:
प्रमेय -> द्रव्य -> अजड -> पराक् i.e.
Knowable -> Substance -> non-material -> external
This is different from the category of Jiva or Ishvara:
प्रमेय -> द्रव्य -> अजड -> प्रत्यक् i.e.
Knowable -> Substance -> non-material -> internal
So it cannot be a "building block" of Jiva or Ishvara.
Dharmabhutajnanam is defined at the beginning of chapter 7:
स्वयंप्रकाशाचेतनत्वे सति, विषयित्वं, विभुत्वे सति प्रभावत् द्रव्यगुणात्मकत्वम्, अर्थप्रकाशत्वं बुद्धिः । तल्लक्षणम् ।
In the case of being self-revealing but non-conscious, it shows the characteristic of a subject (i.e. the one that gains knowledge of objects). In the case of being all-pervasive, it shows the characteristic of being attributes of objects, just as light (carries the attributes of objects it falls on). It is of the nature of revealing objects. This is the definition.
Further it says:
सद् धर्मभूतज्ञानं ईश्वरस्य नित्यानां च सर्वदा नित्यमेव विभु च । बद्धानां तिरोहितमेव । मुक्तानां पूर्वं तिरोहितमनन्तरमाविर्भूतम् ।
This Dharmabhutajnanam is forever eternal and all-pervasive for Ishvara and the Nitya Jivas. For Baddha Jivas, it is covered. For Mukta Jivas, it is covered at first, but revealed afterwards (i.e. after liberation).
Dhamabhutajnana is not a building block of cit and Isvara but it is an attribute of both.
Dharmabhutajnana is the means by which Cit or Jiva experiences the Universe external to itself. It is compared the the light that comes out of a lamp and illuminates the world. It is classified as a substance. However it has no independent existence other than in association with a Jiva or Isvara. Hence it is an attribute of Jiva or Isvara.
Reference: Vedanta Karikavali of Bucci Venkatacharya Chapter 7.