Chapter 22: 4-6
Laws Pertaining to Tachanun
4. One is required to "fall on one's face;" only in a place where a Torah
scroll is present. If there is no Torah scroll, even though there are other
sacred texts, one need not "fall on one's face."* Rather, the psalm is
recited without "falling on one's face." Nevertheless, when prayers are
recited in the courtyard before the synagogue and the entrance to the
synagogue is open, it is considered as if a Torah scroll is present.
* {The Mishnoh Beruroh 131:11 mentions opinions which require "falling on
one's face" in the presence of sacred texts even though a Torah scroll is
not present}
5. Tachanun is not recited when praying in the house of a mourner or in the
home of the deceased, even when no mourner is present, throughout the
entire seven days of mourning. This applies even during the afternoon
service of the seventh day. After [those attending services there] return
to their own homes, they do not recite Tachanun.
If a mourner is present in the synagogue, he does not recite Tachanun.
Nevertheless, the entire congregation does not follow him; they do recite
these prayers.
6.Tachanun is not recited in a synagogue where a bris will be held.
Similarly, should the father of the child to be circumcised, the sandek, or
the mohel be praying there, Tachanun is omitted even if the bris will be
held elsewhere.
In the afternoon service is recited, either before or during the meal, in
the house where the child whose bris is being celebrated is present,
Tachanun is also omitted. However, if those prayers are recited following
the grace after meals, Tachanun should be said. Nevertheless, the child's
father, the sandek, and the mohel should not recite Tachanun even after the
grace after meals, for the day is considered as a festival for them.