:3 Sweetly, the line was something that Bogart said /off-camera/ to Bergman while playing cards between scenes. It was so effortlessly charming, it was brought into the film.
^u^ It's said a total of four times throughout.
Man...I've been thinking nonstop about the works of art this film has influenced and it keeps going and going...the latest thing I see if X-men, where Xavier meets Farouk, the Shadow King