Big case: let it stand outside by raised earth (5,5)

I believe the answer is:

state trial

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'big case let it' is the definition.
I can't tell whether this definition defines the answer.

'stand outside by raised earth' is the wordplay.
'stand' becomes 'stet'.
'outside' means one lot of letters goes inside another (some letters go outside others).
'by' becomes 'at'.
'raised earth' becomes 'rial' (I can't justify this - if you can you should believe this answer much more).
'stet' going around 'at' is 'statet'.
'statet'+'rial'='STATE-TRIAL'

Can you help me to learn more?

I've seen this clue in The Independent.

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