There are some spam issues in the comments, so I had to disable comment editing for a short time. It'll be back once the spam bots are gone. FYI... they leave a comment with "great" and then edit in the spam stuff later, to get around the filter.
(Usually used in where-questions, in contexts where someone doesn't know from where to get something in a certain situation. Implies difficulty. NOT idiomatic when explaining where you got something from.)