Chapter 19: 4-6
Laws Pertaining to Additions
4.. [The following rules apply] should a person err and recite mashiv
horuach... in the summer: If he remembered before concluding the blessing
mechayeh hameisim, he should begin again Attoh gibbor. (This repetition is
instituted so that the blessing will be distinguished as one in which
mashiv horuach... is not recited.) However, if he remembered only after he
concluded the blessing mechayeh hameisim, he must repeat the Shemoneh Esreh
from its beginning.
If he recited only mashiv horuach without concluding umorid hagoshem, there
is no difficulty, and he may continue mechalel chayim...
If one erred and recited [mashiv horuach umorid hagoshem] in the evening or
morning service of Shemini Atzeres itself, there is no need to repeat one's
prayers.
5. We begin requesting tal umotor (dew and rain), [adding the words v'sain
tal umotor to the Boreich oleinu,] from the evening service of the sixtieth
day after the fall equinox.* This always falls on the fourth or fifth of
December. ** We continue making this addition until Pesach.
* {The above applies only in the diaspora. In Eretz Yisroel, the request
for rain is added from the seventh of Marcheshvan.
A question exists regarding when those living in the southern hemisphere
should request rain.}
** {From the year 1900 (until the year 2100), this day will fall on the
fifth of December, except when the coming secular year will be a leap year.
In that instance, it will fall on the sixth of December.}
6. [The following rules apply] should a person err and fail to recite
v'sain tal umotor: If he remembers before he completes the blessing
m'vorech hashomin, he should recite V'sain tal umotor livrochoh al p'nei
ho'adomoh and continue v'sab'einu... and conclude the blessing as usual.
If he remembers after he concludes that blessing,* he should continue
praying and in the midst of the blessing Shem Koleinu, after reciting
reykom al t'shiveinu, he should recite v'saim tal umotor livrochoh and then
continue ki Attoh shome'a tefillas...**
* {If one has not begun the blessing T'ka b'shofor godol, one may still
recite v'sain tal umotor and fulfill one's obligation.}
** {If one has not begun the blessing R'tzeh, one may still recite v'sain
tal umotor and fulfill one's obligation (Shulchon Oruch, Orach Chayim 117:5).}
However, if one did not recall until one finished the blessing shome'a
tefilloh, one must return and begin again from the blessing Boreich oleinu.
If one did not remember until after reciting the verse Yih'yu l'rotzon [at
the conclusion of the Shemoneh Esreh], one must recite the entire Shemoneh
Esreh again.
