Sources based on Rav Elyakim Krumbein's "Mussar for Moderns" shiurim, Shiur #14: Ethical Ascent Through Prayer (Part 1) and Shiur #15: Ethical Ascent Through Prayer (Part 2)
https://torah.etzion.org.il/en/shiur-14-ethical-ascent-through-prayer-part-1
https://torah.etzion.org.il/en/shiur-15-ethical-ascent-through-prayer-part-2
(א) הַהִתְבּוֹדְדוּת הוּא מַעֲלָה עֶלְיוֹנָה וּגְדוֹלָה מִן הַכֹּל, דְּהַיְנוּ לִקְבֹּעַ לוֹ עַל־כָּל־פָּנִים שָׁעָה אוֹ יוֹתֵר לְהִתְבּוֹדֵד לְבַדּוֹ בְּאֵיזֶה חֶדֶר אוֹ בַּשָּׂדֶה, וּלְפָרֵשׁ שִׂיחָתוֹ בֵּינוֹ לְבֵין קוֹנוֹ בִּטְעָנוֹת וַאֲמַתְלָאוֹת, בְּדִבְרֵי חֵן וְרִצּוּי וּפִיּוּס, לְבַקֵּשׁ וּלְהִתְחַנֵּן מִלְּפָנָיו יִתְבָּרַךְ, שֶׁיְּקָרְבוֹ אֵלָיו לַעֲבוֹדָתוֹ בֶּאֱמֶת. וּתְפִלָּה וְשִׂיחָה זוֹ יִהְיֶה בַּלָּשׁוֹן שֶׁמְּדַבְּרִים בּוֹ, דְּהַיְנוּ בִּלְשׁוֹן אַשְׁכְּנַז (בִּמְדִינָתֵנוּ), כִּי בִּלְשׁוֹן־הַקֹּדֶשׁ קָשֶׁה לוֹ לְפָרֵשׁ כָּל שִׂיחָתוֹ... וְאֶת כָּל אֲשֶׁר עִם לְבָבוֹ יָשִׂיחַ וִיסַפֵּר לְפָנָיו יִתְבָּרַךְ, הֵן חֲרָטָה וּתְשׁוּבָה עַל הֶעָבָר, וְהֵן בַּקָּשַׁת תַחֲנוּנִים לִזְכּוֹת לְהִתְקָרֵב אֵלָיו יִתְבָּרַךְ מֵהַיּוֹם וְהָלְאָה בֶּאֱמֶת, וְכַיּוֹצֵא בָּזֶה כָּל חַד לְפוּם דַּרְגֵּהּ. וְיִזָּהֵר מְאֹד לְהַרְגִּיל עַצְמוֹ לְהַתְמִיד בָּזֶה מִדֵּי יוֹם בְּיוֹם שָׁעָה מְיֻחֶדֶת כַּנַּ"ל, וּשְׁאָר הַיּוֹם יִהְיֶה בְּשִׂמְחָה כַּנַּ"ל... וַאֲפִלּוּ אִם לִפְעָמִים נִסְתַּתְּמִין דְּבָרָיו, וְאֵינוֹ יָכוֹל לִפְתֹּחַ פִּיו לְדַבֵּר לְפָנָיו יִתְבָּרַךְ כְּלָל, אַף־עַל־פִּי־כֵן זֶה בְּעַצְמוֹ טוֹב מְאֹד, דְּהַיְנוּ הַהֲכָנָה שֶׁהוּא מוּכָן וְעוֹמֵד לְפָנָיו יִתְבָּרַךְ, וְחָפֵץ וּמִשְׁתּוֹקֵק לְדַבֵּר, אַךְ שֶׁאֵינוֹ יָכוֹל, זֶה בְּעַצְמוֹ גַם־כֵּן טוֹב מְאֹד, וְגַם יוּכַל לַעֲשׂוֹת לוֹ שִׂיחָה וּתְפִלָּה מִזֶּה בְּעַצְמוֹ. וְעַל זֶה בְּעַצְמוֹ יִצְעֹק וְיִתְחַנֵּן לְפָנָיו יִתְבָּרַךְ, שֶׁנִּתְרַחֵק כָּל־כָּךְ, עַד שֶׁאֵינוֹ יָכוֹל אֲפִלּוּ לְדַבֵּר... וְדַע, שֶׁכַּמָּה וְכַמָּה צַדִּיקִים גְּדוֹלִים מְפֻרְסָמִים סִפְּרוּ, שֶׁלֹּא בָּאוּ לְמַדְרֵגָתָם, רַק עַל־יְדֵי הַנְהָגָה זוֹ.
"Hitbodedut" is the highest level of all, which means to set aside an hour or more to seclude herself in a room or in a field, and to have express herself in dialogue with her Creator, with claims, words of favor, and to request and supplicate before G!d that G!d should bring her close to G!d's service. And this prayer should be in one's native language which is German (in our country), because in Hebrew it is hard to express oneself, and the heart isn't drawn after such words... And she should speak what is in her heart, whether it be regret and teshuva on the past, or supplications to merit to come close to G!d in truth from that day on, and similar things, each according to her level. And she should be accustom herself to do this every day at a designated time, and the rest of the day she should be happy. And even if sometimes she doesn't have anything to say, she should speak to G!d about not having anything to say, and she should cry out to G!d, that she is so far away that she doesn't even know what to say... And you should know, that many righteous people said that they only reached their level because of this practice.
מי יתן והיה לבבם וגו' ה"ל לומר תן כו'. גם שאמרו הכל בידי שמים חוץ מיראת שמים מ"מ פשיטא דביד הקב"ה להטות לב בני אדם לטובה דכמה כתובים מורים ע"ז וכמ"ש לעיל וקאמר דמשה לא רמזה כו' דכתיב ולא נתן לכם לב לדעת וכו' דהיינו שרמזה להם שיש ביד הקב"ה לתת ולהטות לבם לטובה והם כפויי טובה ולא שאלו לו על כך
From all this it is clear to the eye to what extent Chazal encouraged hitbodedut, that is - expression in speech before God, blessed be He, and beseeching Him that He give us fear of Heaven so that we do not sin, even though "all is in the hands of Heaven except for fear of heaven," still - everything is in His hand. One must pray to God Himself for this, as it says explicitly in this gemara, that Moshe criticized them severely and called them "ungrateful" because they didn't say to God, "You give us," i.e. that God give them fear of Heaven...
God can intervene to help make us more ethical, G-d-fearing
What about free choice?
At first glance, one can raise a difficulty regarding the practice of hitbodedut and conversation with one's Maker ... and also regarding the fact that all the righteous ones of old did this and composed numerous prayers in order to merit being saved from the yezter ha-ra and to merit becoming close to God ... Now Chazal said that "Everything is in the hands of Heaven except the fear of Heaven." If so, how is it possible to pray for this, since God has given the choice over to us exclusively? But the truth is that this itself is the main choice of man, because it is impossible for one to merit wholeness and to loathe evil and choose good and attain what one is supposed to attain in this world simply by using one's choice, but only by multiplying prayers and entreaties ... so that the multitude of evil waters - the evil desires of this world that are constantly raging - should not wash him away ... For even though man has free choice, the main thing is to pray and beseech God about this, because choice - the power to choose good and despise evil - is in the mind, but the human mind only has the power to subdue lusts and kelipot (= spiritual sources of defilement) which come from that aspect of heresy that results from the "breaking of the vessels," which hold sparks of holiness that are sparks of intelligence ... But there are confusions and "other sides" (= euphemism for yetzer ha-ra) and obstacles to holiness that come from the aspect of "the empty space," where His Divinity cannot be found through any intelligence or wisdom, BUT ONLY BY FAITH ALONE, and this is the aspect of prayer, entreaties and cries to God, that He save us from the kelipot and the yetzer ha-ra that come from there ... For in no way can one be saved from the yetzer ha-ra that comes from the "empty space" with free choice and mind alone, but only with Divine assistance ... because there intelligence is of no avail, but on the contrary, there intelligence and wisdom can cause one to sink even more, God forbid.
But Rav Nachman thinks that this source of evil is not the main problem. There are moral defects in the world which do not stem from lack of proper thinking, but from lack of faith. All of the great thinkers who arrived at conclusions with negative - even disastrous - moral repercussions, were not guilty of faulty argumentation. They merely demonstrated that in the "empty space" - the realm where the evil comes about because of the "lack" (so to speak) of Divinity - intelligence can make matters worse, by weakening faith. Rav Nachman here makes a daring statement about the fundamental inability of intelligence to find truth..
...Faith is...a weapon to be used against the confusion generated by the evil of the "empty space." The prayer-effort is an expression and a deepening of faith, and Rav Nachman requires this effort to be an ongoing one. The resulting spiritual ascent, when it comes, is the answer to a prayer. Therefore it is the result of free Divine intervention, but on the other hand - of human striving as well.
[" https://torah.etzion.org.il/en/shiur-14-ethical-ascent-through-prayer-part-1"]
- "Giving knowledge an existential turn"
Also it is good to make a prayer out of the Torah. That is, when one learns or hears a sermon of Torah from a true tzaddik, then he should make a prayer out of it. In other words, to ask and beseech God for all [the spiritual levels] that are discussed in that sermon, when will he merit that he too should attain all of this, and how far-removed he is from this, and he should ask God to grant that he attain whatever is discussed in that sermon...
This prayer and this speech should be in the spoken language, that is Yiddish (in our country), because in the holy tongue (Hebrew) it will be difficult for him to express whatever he wants to say, and also the heart will not flow after the words because he is not used to the language ... but in Yiddish he can express whatever he wants to say and whatever is on his heart he can say and talk about before Him, blessed be He, whether it be regret and penitence about the past or entreaties to merit actual nearness to Him from this day on...
Until he is very close to having his soul leave him, God forbid, until he almost dies, God forbid, until his soul remains connected to his body only with a thread, as a result of his great pain, yearning and pining for God. As Chazal said (Ta'anit 8a), "No man's prayer is heard until he takes his soul in the palm of his hand"...
All the prosecuting angels and destroyers know all about the standard formulated prayers, and they lie in wait for them on the roads. Metaphorically, it is like the well-paved road that everyone knows, where the murderers and thieves always lie in wait because they have known the road for a long time. But when people go on a new road which no one knows yet, there they don't know where to lie in wait. So it is in our matter, because the conversation that one has with his Maker is a new way and a new prayer which a person says anew from his heart. That is why there are fewer prosecutors lying in wait. But nevertheless, he (Rav Nachman) cautioned often regarding the saying of the other (i.e. standard) prayers as well...
Praying in Solitude, Praying in Nature
The winter is a kind of gestation period, when all the grasses and plants are dead ... But when summer comes, it is like a rebirth, and all the grasses wake up and live, and then it is very good and beautiful to go out and pray in the field ("lasuach ba-sadeh"), [as Chazal said,] "Sicha is prayer" and entreaties and desire and yearning for God. And then all the bushes of the field yearn, and are included in his prayer ... He (Rav Nachman) said that if only one were to merit to hear the songs and praises of the grasses, how each and every one sings to God without any self-interest or foreign thought, how beautiful and seemly it is to hear their singing. Therefore it is very good to fear God in their midst, to be alone in the field among the plants of the earth and truly pour out one's prayer before God.
- What if the spontaneous prayer doesn't flow?
And even if sometimes his words are stopped up and he cannot open his mouth to speak before Him at all, this itself is very good ...
(Hishtapkhut Ha-nefesh, 2):
[T]his state of readiness, that he is poised before Him and desires to speak but cannot, this itself is also very good. And he can also make a speech and a prayer out of this itself; and about this situation itself he may cry out and beseech before God that he is so far gone that he can't even speak; and he may request from Him mercy and entreaties, that He should have pity on him and open his mouth so that he may express himself in speech before God...
Silence as Prayer
But even with regard the words of prayer themselves, one cannot be prematurely hasty, as in the case of anyone who would like that at the moment he begins hitbodedut in order to express himself in speech before God, his mouth will be opened and will immediately speak perfectly, words as warm as fiery coals, and with great arousal. But since not everyone merits this, and every time it seems to him that he has nothing to say and no arousal at all, he becomes lax... Therefore one should know well, that this too is premature haste, for it is impossible to draw out perfect speech without the silence and expectation which precedes speech. Because first one has to be still and silent and only wait and yearn and pine and long for the favor of God, that He grant him perfect speech...