Universal god is deceived in sacred book (9)

I believe the answer is:

upanishad

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'sacred book' is the definition.
The definition suggests a singular noun which matches the answer.

'universal god is deceived' is the wordplay.
'universal' becomes 'u'.
'god' becomes 'pan' (Pan is an example).
'deceived' becomes 'had' (I've seen this in other clues).
'u'+'pan'+'is'+'had'='UPANISHAD'

'in' is the link.

Can you help me to learn more?

(Another definition for upanishad that I've seen is " text in Sanskrit".)

I've seen this clue in The Independent.

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