Speak falsely yet be quiet (3,5)

I believe the answer is:

lie still

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'speak falsely yet' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'be quiet' is the wordplay.
'be' becomes 'lie' (lying is a kind of being).
'quiet' becomes 'still' (synonyms).
'lie'+'still'='LIE STILL'

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I've seen this clue in The Globe and Mail.

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