Staying in bed, say, a great honour for a body (5,2,5)

I believe the answer is:

lying in state

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'a great honour for a body' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'staying in bed' is the wordplay.
I cannot quite understand how this works, but
'in' is found in the answer.
an anagram of 'staying' is 'yginsta' which is present in the remaining letters.
This may be the basis of clue (or it may be nonsense).

'say' acts as a link.

Can you help me to learn more?

I've seen this clue in The Guardian.

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