purANa in chAndogyopanishad?

[Robert, Eric]

Dear list members

In chAndogya upanishad 3.4.1&2, one finds mention of itihAsa and purANa
(e.g. in 3.4.1...the flower being the itihAsa and the purANa, which are also
the immortal waters).
A similar mention occurs in 7.1.2.
The chAndogya being one of the oldest upanishad, are these passages a later
addition, or do itihAsa and purANa have another meaning here than their
normal meaning (the date for the composition or elaboration of the epics
seems subject to discussion, but I think that early purANas are dated from
the beginning of this era, or am I wrong?).

Thanks for your comments

Eric Robert