Remembering the Destruction of Jerusalem 2. Similarly, [as a
reminder of the destruction of Jerusalem, the Sages] ordained
that when one makes a feast for guests, even a feast associated
with a mitzvah, one should not serve all the dishes that would
ordinarily be served at such a feast (1). Similarly, a woman
should not wear all her jewelry at one time (2). [At a wedding,]
a groom should place ashes on his head, on the place where he
wears Tefillin. The veil used to cover the bride should not
contain strands of silver or gold. Similarly, it is customary
that when drawing up the engagement contract ("t'no'im"), a dish
is broken, as a remembrance of the destruction; however, one
should use a dish that is already broken. Under the wedding
canopy, the bridegroom should break a glass vessel; a whole
glass may be used (3). (1) Omitting even one minor item is
sufficient. On Shabbos and Yom Tov however, nothing should be
omitted from the traditional three meals, because publicly
showing signs of mourning on Shabbos i