Chapter 21: 4-5
Laws of Missed Prayers
4. Even on a day which the musaf service is recited, if one failed to
recite the morning service, one may compensate for it in the afternoon
service. (Since the time for the musaf service extends until night, if
necessary, it is not regarded as though the time for two services has passed.)
However, if the time for the morning service has passed and one has recited
the musaf service, he is not able to compensate for the morning service [by
reciting the musaf again]. (Since it mentions the musaf sacrifices [offered
after the daily morning service], it is not an appropriate substitute for
the morning service.) Nevertheless, if the time for the morning service has
not passed, even though one has recited the musaf service he may recite the
morning service.
5. One can compensate only for a Shemoneh Esreh which was not recited
during the time of the following prayer service, but not during a time
which is not a time of prayer. For example, a person who waited a long time
after reciting the service which he was obligated at that time, can no
longer compensate for a service which he failed to recite. [For example, a
person failed to recite the morning service, and later recited the
afternoon service in its proper time. After he waited an hour, he desired
to compensate for the morning service which he omitted. This is not allowed
even though the sun has not set and, thus the time for the afternoon
service has not passed.]
[The rationale for this decision is that the Sages] decreed that
compensation for a prayer one failed to recite is allowed only during the
time one is reciting a prayer service which is then obligatory. While one
is involved in other prayers, one may compensate for prayers one failed to
recite.*
* {The Mishnoh Beruroh 108:15 allows one to compensate for the omitted
prayer in such circumstances.}
