Rif Brachot 20a

20a

{Brachot 29a continued}
able to say it in {the blessing of} Shomea' Tefilla {Who Hears Our Prayers}.
And these words are said regarding when he recalls {his error} before Shomea' Tefilla, but if he does not recall before {finishing} Shomea' Tefilla, they cause him to return.
And if he errs and does not say havdala in Chonen HaDaat, they do not cause him to return, for he is able to say it over the cup.

{Brachot 29b}
Rabbi Tanchum cited Rabbi Assi who cited Rabbi Yehoshua ben Levi: If he erred and did not mention the head of the month {Rosh Chodesh} - in Avodah {=the 16th blessing, which starts Retzei}, he returns to Avodah. In Sim Shalom {Give Peace} and Hodaah {=Thanksgiving = Modim}, he returns to Avodah. And if he finished {Shemoneh Esrei} he returns to the {very} beginning.

Rav Papa son of Rav Acha bar Ada said: This that you said "If he finished he returns to the beginning" - was only said where he uprooted his legs. But, if he did not uproot his legs, he returns to Avodah.

Rav Nachman bar Yitzchak said: This that you said "as long as he did not uproot his legs" - was only said when he is accustomed to recite after his prayer supplications {such as Elokai Netzor}, but if he is not accustomed to recite after his prayer supplications, he must return to the {very} beginning.

And so is the halacha.

Mishna:
R. ELIEZER SAYS: IF A MAN MAKES HIS PRAYERS A FIXED TASK, IT IS NOT A [GENUINE] SUPPLICATION.
R. JOSHUA SAYS: IF ONE IS TRAVELLING IN A DANGEROUS PLACE, HE SAYS A SHORT PRAYER, SAYING:
SAVE, O LORD, YOUR PEOPLE THE REMNANT OF ISRAEL; IN EVERY TIME OF CRISIS MAY THEIR REQUIREMENTS NOT BE LOST SIGHT OF BY YOU. BLESSED ARE YOU, O LORD, WHO HEARKENS TO PRAYER.

Gemara:
What is "fixed?"
Rav Yaakov bar Iddi cited Rav Hoshaya: One whose prayer seems upon him like a burden.
And the Sages say: One who does not say it in the language {way} of supplication.

The Sages learnt {in a brayta}: one who travels in a place infested with beasts or bandits should pray a short prayer. What is a short prayer? {The Rif skips the opinions of R Eliezer and R Eliezer beRabbi Tzadok.} Others say: The needs of Your people Israel are many and their attentions {thoughts} are short. May it be Your will, O Lord our God, to give to each one his sustenance and to each body what it lacks. Blessed are You, O Lord, who hearkens unto prayer.

R. Huna said, and some say Rabbi Yehoshua ben Levi: The halacha follows the 'Others'.

Eliyahu said to Rav Yehuda the brother of Rav Sela Chasida {=the Pious}: Don't get angry so that you don't sin. Don't drink excessively so that you don't sin. And when you go out on the road, consult with your Maker and go.
What is this?
Rabbi Yaakov cited Rav Chisda: This is tefillat haDerech {The prayer for the road = journey}.

And Rabbi Yaakov cited Rav Chisda: One who sets out on the road must say tefillat haDerech.
What is tefillat haDerech?
'May it be Yourwill, O Lord my God, to lead me forth in peace, and direct my steps in peace and uphold me in peace, and deliver me from the hand of every enemy and ambush by the way, and send a blessing on the works of my hands, and cause me to find grace, kindness, and mercy in Your eyes and in the eyes of all who see me. Blessed are You, O Lord, who hearkens unto prayer'

Abaye said: One should always partner {=associate} himself with the congregation {and thus
should change all the first person singular in the above prayer to first person plural}.

{Brachot 30a}
When should he pray it?
Rabbi Yaakov cited Rav Chisda: At the moment he starts on his journey.
And until when can he say it? Until a parsa.
How should he pray it?