If you read correctly the discussion the user is talking about post/content published by someone else. I think it's clear for every reader. So your answer is totally useless

@OP
The use of cache from a search engine is the best you could get unless you take action before. You could for example use IFTTT to archive what you're looking for and to read it later

If a tweet is posted>save it to google drive (or alternative), post it ti FB (or alternative), post it to WordPress as draft etc.
You will have to make an RSS for the concerned account.

There are several options