Chapter 141:21
Laws of the Megillah
21. [The following laws apply to] a person whose immediate relative (1)
dies on the "Fast of Esther" (the day before Purim), and at night (that is,
Purim) he is an "onen" [because] it is before the burial (2): He should
hear the Megillah read by another person (3), but should not eat meat or
drink wine, for there is no obligation for him to have a feast ("mishteh")
on the night [of Purim]. The next morning, after people have left the
synagogue (that is, after the congregation has heard the Megillah), the
deceased is buried (4) and afterwards the [mourner] should say the morning
prayers ("yispallel") and read the Megillah or listen to it being read by
another person (5). A mourner who hears the reading of the Megillah before
the burial of his dead does, however, fulfill his obligation. It is,
nevertheless, proper for him to read it again without reciting the
blessings (6). He should not, however, wear tefillin even after the burial,
since this is the first day of one's mourning (7). During the day of Purim,
an "onen" is allowed to eat meat and drink wine (8).
FOOTNOTES:
(1) Parents, siblings, children or spouse.
(2) Before the burial a mourner is considered an "onen" and is bound by
laws which are slightly different to those of a mourner after the burial.
(3) The reason he shouldn't recite the blessings and read the Megillah
himself is because there are authorities who rule that on Purim night all
the laws of an "onen" apply, and he is thus exempt from all mitzvos,
including hearing the Megillah. There are those who disagree and rule that
the mitzvos of Purim take precedence over the mitzvos of mourning, and
therefore, the "onen" would be obligated to hear the Megillah (See Shulchan
Aruch and Rama 296:7 and Mishna Berura 24-26).
(4) According to many authorities, the congregation's obligation to hear
the Megillah takes precedence over the congregation's obligation to help
out with burying the dead. Therefore, the custom is that the burial takes
place only after the Megillah is read for the congregation in synagogue
(Mishna Berura 296:26).
(5) As we saw earlier, before the burial the "onen" is exempt from all
mitzvos.
(6) This is because there are authorities who rule that if a mourner hears
the Megillah before the burial, he has not fulfilled his obligation because
at the time he was listening, he was exempt from all mitzvos (Ibid.).
(7) See Kitzur Shulchan Aruch: Chapter 211:2
(8) As we saw earlier, the mitzvos of Purim take precedence over the
mitzvos of mourning.