What is the connection between an ox that gores and saying Morid Hageshem?

As we have learned, once new additions to Shemoneh Esrei have been recited for thirty days or ninety tefillos, one who can’t remember what he said can trust that he recited the correct nusach. If one does ninety practice runs of the brocha with the correct addition, the Rishonim disagree about whether he can then be established as fluent in the text. Some bring a proof from halachos pertaining to oxen. Once an ox has gored three times, it is a mu’ad (established as one that gores) and the owner is obligated to pay full damages if it subsequently causes harm. According to one view in the Mishnah, the ox becomes a mu’ad whether it gored three times over three days or three times in a day. The reasoning is that if one can establish a tendency from actions spread over several days, certainly he can establish one based on multiple actions in a day. Likewise, if one can establish fluency over thirty days, he can certainly establish it after multiple reviews in one day. Others reject this proof for various reasons. Shulchon Aruch rules that it is effective, while some other Achronim hold that it is not.

סי' קי"ד ס"ט ביה"ל ד"ה אם

Can one practice an omission?

Rema rules that ninety practice runs can be used both in the summer and winter. In the winter, one should begin with the words mechaye meisim Atah and continue with mashiv haruach. In the summer, one should begin at the same point, omit mashiv haruach, and finish with the words mechalkel chaim. Others disagree with this last point and hold that one cannot practice by omitting words. There are some Achronim who rule that a person should do one-hundred-and-one practice runs instead of ninety. Some contemporary poskim rule that a person should not rely on the solution of practice runs. Since, as mentioned, its efficacy is subject to a disagreement among the poskim, they hold that it is best to avoid it.

ס"ט ס"ק ל"ט, מ"א, מ"ג ביאוירם ומוספים דרשו 45, 51

What is the proper mindset that a person should have during the brocha of Selach Lonu?

During the brocha of Selach Lonu, a person should think about specific sins that he may have done and make up his mind to rectify them. There is a custom to hit one’s heart with his fist. This is a symbolic gesture of chastising the heart for causing the sin. Some have the custom of not hitting the heart on days when tachanun is not said. The chazan should follow the custom of hitting his heart during Chazoras Hashatz.

סי' קט"ו ס"ק א' ביאורים ומוספים דרשו 3, 4

• According to some Achronim, the term “thirty days” that is used by Shulchon Aruch actually refers to ninety tefillos. In that case, one would reach the milestone of being able to trust that he said Morid Hatal/Geshem before thirty days have passed (since on some days there are four tefillos). Conversely, one would need to wait for more than thirty days in order to trust that he said V’sein Tal, since this tefilla is only recited during the week.

• Other poskim disagree and hold that thirty days is to be taken literally, even if in some cases it may involve more or less than ninety tefillos. in some instances, this view is more stringent than the first opinion (regarding Morid Hageshem/Tal) and other times it is more lenient (regarding V’sein Tal Umatar). Based on the rule that we do not recite extra brochos when we are in doubt, one should always take the more lenient position and try to refrain from repeating Shemoneh Esrei.

• If a person mistakenly says the wrong verse one day during the thirty-day period, the poskim discuss whether that day counts and, if it does not count, whether he must restart the entire thirty-day count. Later poskim rule that it does not count, but it also does not invalidate the days that he already counted; he may continue counting until he reaches thirty days.

• Is there a mitzvah to daven for the health of others?

• How should a mother daven for a child who is ill?

• When should a visitor to Eretz Yisroel begin saying V’Sein Tal Umatar?