Chapter 17: 9-10
Recitation of the Shema
9. When a person who is forced to make an interruption in the midst of the
recitation of the Shema (i.e., in the portions from Shema Yisroel until al
ho'oretz*) - for example, he had to relieve himself or feces were found in
the place where he was praying - he must return to the beginning of the
Shema if he was forced to wait for the amount of time it takes for him to
recite the Shema.
* {Other halachic authorities do not exclude the passage Vayomer.}
10. A person who already recited the Shema and enters a synagogue where he
finds the congregation reciting the Shema, should also recite the entire
Shema* together with them, so that it does not appear that he does not
desire to accept the yoke of heaven together with his colleagues. He
receives a reward as one who reads from the Torah.
* {Though it is preferable to recite the entire Shema, the Ramoh (Shulchon
Oruch, Oruch Chayim 65:3) requires recitation of only the initial verse.}
The same applies to a person in the synagogue who is reciting prayers of
supplication or other verses in a place where it is permitted to make an
interruption. (The laws applying to one who is at a point of the service
where he cannot make an interruption are explained above [Chapter 14, Law
1; Chapter 16, Law 2]).
If one has not yet recited the Shema, he should recite it with the
congregation. However, he should have the intention not to fulfill his
obligation to recite the Shema, so that he may recite it later, together
with its blessings.
These principle apply regarding all other prayers recited by the congregation
- e.g., Tehilloh l'Dovid (Ashrei), Oleinu, and the like. Even liturgical
chants should be recited with them, so that one does not separate oneself
from the congregation.
