The breaking of the glass in Jewish weddings, in which the groom crushes a glass under his foot at the end of the ceremony, is a tradition with murky roots. Some hold that the breaking glass symbolizes the destruction of the great Temple in Jerusalem in A.D. 70, while others say that the broken glass is a reminder that joy should always be tempered. Either way, breaking the glass is usually undertaken in the spirit of happiness today, with wedding guests calling out "mazel tov!" (good luck!) after the glass shatters.