Scripture is just great when read regularly (5)

I believe the answer is:

sutra

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'scripture' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for sutra that I've seen before include "sacred text" , "Book of aphorisms" , "A Buddhist scripture" , "Sanskrit aphorisms" , "old rule book" .)

I've seen this clue in The Times and The Sunday Times.

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