Quoting Quoting an author - explained

The name of the author initiates a search in our memory for texts that we have read by the same author to see if it coincides with the quotation. If it doesn't, the other texts might produce a categorical description, through their significance, that may even suffice for the purpose of the quote(see Michel Foucault - What is an author?, he is critised for failing to properly describe Buffon and his work). If quote has no significance at all, then the author who quotes it provides the significance by its contextual clue.So?????