How can I save a text?

[iMore Question]

But only view the last 24 hours of the conversation?

 

[Ledsteplin]

Welcome to iMore! Depends on what you want to do with them. You can save all your text conversations by going to settings > Messages > scroll down to "keep messages" > Set to "forever".
For just one or a few, you'll need to screenshot the message/messages, and put them somewhere like in Dropbox or Box.