as I live and breathe

Wow! An expression of surprise or amazement. As I live and breathe! I haven't seen you in years!

Fig. How amazing! (Said on seeing or experiencing something surprising.) As I live and breathe, here we are again! Well, as I live and breathe, it's Harry Smith!

For sure, definitely, as in As I live and breathe, I've never seen a more beautiful view. This expression is generally used to emphasize the truth of a statement and has been so used since the mid-1600s, although sometimes it was put simply as as I live. However, the complete phrase was also used early on, as in Arthur Murphy's 1756 play The Apprentice (2:1): "As I live and breathe, we shall both be taken, for heaven's sake let us make our escape."

I am certain, I am confident. This redundant phrase—one can’t be alive and not breathe—is usually stated with a sense of mild surprise. It began life as simply as I live in the mid-1600s and continues to be used as an intensifier—for example, “As I live and breathe, he’s gone and bought another new car”—but is heard less often today.