MISHNA: The mishna cites a dispute with regard to the obligation to recite the Amida prayer, also known as Shemoneh Esreh, the prayer of eighteen blessings, or simply as tefilla, prayer. Rabban Gamliel says: Each and every day a person recites the prayer of eighteen blessings. Rabbi Yehoshua says: A short prayer is sufficient, and one only recites an abridged version of the prayer of eighteen blessings. Rabbi Akiva says an intermediate opinion: If he is fluent in his prayer, he recites the prayer of eighteen blessings, and if not, he need only recite an abridged version of the prayer of eighteen blessings. Rabbi Eliezer says: One whose prayer is fixed, his prayer is not supplication and is flawed. The Gemara will clarify the halakhic implications of this flaw.

On a similar note, the Gemara recounts related stories with different approaches. The Sages taught: When Rabbi Eliezer fell ill, his students entered to visit him. They said to him: Teach us paths of life, guidelines by which to live, and we will thereby merit the life of the World-to-Come. He said to them: Be vigilant in the honor of your counterparts, and prevent your children from logic when studying verses that tend toward heresy (ge’onim), and place your children, while they are still young, between the knees of Torah scholars, and when you pray, know before Whom you stand. For doing that, you will merit the life of the World-to-Come.

We learned in the mishna that Rabbi Eliezer says: One whose prayer is fixed, his prayer is not supplication. The Gemara asks: What is the meaning of fixed in this context? Rabbi Ya’akov bar Idi said that Rabbi Oshaya said: It means anyone for whom his prayer is like a burden upon him, from which he seeks to be quickly unburdened. The Rabbis say: This refers to anyone who does not recite prayer in the language of supplication, but as a standardized recitation without emotion. Rabba and Rav Yosef both said: It refers to anyone unable to introduce a novel element, i.e., something personal reflecting his personal needs, to his prayer, and only recites the standard formula. Rabbi Zeira said: I could introduce a novel element in every prayer, but I am afraid that perhaps I will become confused. Consequently, there is no room to require the masses to introduce a novel element into their prayers.

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(15) ...Inner mindfulness: how does one attain it? Any prayer for which one is not fully mindful is not considered prayer. And if one prays without mindfulness, one must go back and pray [again, this time] with mindfulness. One who is confused or inwardly agitated is forbidden from praying until he settles himself; thus, one who has come in from traveling and is tired or unsettled is forbidden from praying until he settles himself. The sages used to say that he ought to wait for three days until he has rested and his emotions have cooled, and only afterward may he pray.

If ​ he has kavanah ​ in all of the [berakhot of the Amidah] but does not have ​ kavanah ​ in Avot [the first berakhah], then he needs to go back and pray [again]. But nowadays we don’t go back because of a loss of ​ kavanah, since even with going back to [a place] close [to where he left off], he won’t have ​ kavannah. If that is true why should he go back?