To cleave to your wife, or to cleave to your spouse means to attach to them, to be one with them. It means to owe your allegiance to this relationship over any other. That this person is no.1 in your most important person list. To cleave to your wife means that you will choose her over anyone else. That you will give her and everyone around you the impression that she takes precedence in your life. To cleave to your spouse, is a lifelong commitment that you make for the benefit of your marital life.