From Lord of the Rings:
‘You be careful of yourself, Maggot!’ she called. ‘Don’t go arguing with any foreigners, and come straight back!’
‘I will!’ said he, and drove out of the gate.
Normally we should see here "he said". I've seen the form "said he" a couple of times in literary works to express solemnity, but I don't think that applies here.
When would you say "said he" rather than the common "he said"?