The bride and groom are ideally parts of one soul that have found one another. Only those who have merit succeed in finding their matching soul. When a man does not succeed in doing so, part of that soul is given to another.

All spirits contain [both] male and female [elements]. When they are manifest, they are [both] male and female, and only afterward, [when they descend to this world,] do they go their separate ways. If one has merit, they [the male and female parts] subsequently match up. They are joined together in one union, entirely, in body and soul…. If one merits, he is given his mate, and if not, she is separated from him and given to another. (Zohar 3:43a)