"We'll burn that bridge when we come to it."

[eachase.livejournal.com]

So, I recently read _So You Want to Be a Wizard_ by Diane Duane in which I came across the line, "We'll burn that bridge when we come to it."

I feel like I've come across that line before. Possibly in one of the QT books. But I don't have eBook versions, so I cannot easily confirm or debunk my hypothesis.

So, my questions are:
1. Am I just mis-remembering?
2. Or does the line "We'll burn that bridge when we come to it" appear in one of the QT books?
3. If so, is it a case of that being the sort of line that authors who enjoy word play and twisting common phrases are likely to write independently?
4. Or is it a deliberate Easter Egg referece to _So You Want to Be a Wizard_?