In "Vargtimmen" Max von Sydow's character talks about how extremely long one minute can appear to be and demonstrates it by having an actual minute pass on screen while counting down on his watch. With this scene, Bergman references a scene in Jean-Luc Godard's "Bande a part" released four years earlier in which the characters have a minute of silence in the film.
The plot and themes are essentially the same, with some character names being identical as well as both films being based loosely off the same discarded script