The month of Cheshvan is the month "after the holidays". The festivals of the Torah focus on the summer months (from Nissan to Tishrei), and over the generations, Chanukah (Kislev-Tevet) and Purim (Adar) were added during the winter months – as well as Tu B'Shvat, which is also marked with festivity. The month of Cheshvan remains the only month with no festivals. Hence, Cheshvan is the time to clarify our relationship with the ordinary weekdays.
Sanctifying the Mundane
Judaism instructs us not to withdraw from the physical world. Alongside our aspiration towards spiritual realms, we need to be active participants in reality, to sanctify and improve it. Hence, in the observance of Torah and commandments, "deed is the main thing," and Jewish law addresses countless aspects of life. Moreover, even during our daily routine, when we are not engaged in a specific commandment, we are guided to sanctify all areas of life. The Mishnah in Pirkei Avot states "Let all your deeds be for the sake of Heaven," and the verse in Proverbs says "In all your ways, know Him." It is incumbent upon us to direct ourselves towards the Divine and know God even in our personal pursuits and individual ways – in "your deeds" and "your ways."
Chasidut explains that there is a distinction between "Let all your deeds be for the sake of Heaven" and "In all your ways, know Him." In "Let all your deeds be for the sake of Heaven," the action itself remains a worldly action, but its purpose is to support future matters of Godliness and sanctity – it is directed "for the sake of Heaven." In contrast, in "In all your ways, know Him," the knowledge of God unfolds in the present, within the actual worldly action – "in all your ways" – and thus reveals a dimension of holiness within the action itself.
An example is given in the book of "Tanya" (by Rabbi Shneor Zalman of Liadi, the first Rebbe of Chabad): Science represents the wisdom of the mundane world, and it does not engage with sanctity and values. How can the study of science be sanctified? The "Tanya" offers two approaches:
A person who follows the path of "Let all your deeds be for the sake of Heaven" engages in science to acquire a profession that will sustain him. He may intend to use his free time for Torah study and prayer with a tranquil soul, without financial concerns (of course, he also plans to invest his money in Torah education for his children and in acts of charity and kindness). In this manner, there is no sanctity in the study of science and engagement in it; rather, the ultimate goal is sanctity – the mundane is meant to serve the sacred.
In contrast, for a person who follows "In all your ways, know Him," the study of science itself becomes part of his service of God. Learning exposes the Creator's fingerprint, arouses love and fear of God in the soul, and even integrates into his Torah study. Here, the mundane becomes a part of the sacred.
The first approach is simpler and more common, as it doesn't require a substantial change in the nature of the study itself. It does, however, carry a danger – getting absorbed in the mundaneness of the present and forgetting the future goal. On the other hand, the second, more demanding approach sanctifies the present mundane and encounters God within reality itself. As we strive toward the redemption of the world, our aspiration is to merit the work of "In all your ways, know Him."
Desires of God
Why is it so crucial to sanctify the mundane?
Every individual understands deeply that his well-being lies in filling life with true meaning and not sinking into the trivialities of the mundane. However, beyond that, the sanctification of the mundane is the primary fulfillment of the purpose of creation. The sages teach that "The Holy One, blessed be He, desired to have a dwelling place in the lower realms." The physical world, being so low, seems disconnected from its Creator, even hiding Him behind experiential reality (to the extent that one might misconstrue that the world exists independently of its Creator). Why did God create such a world? Because there was a desire in His "heart" for His presence to dwell precisely within such a distant and foreign reality. (And why is that? The Baal HaTanya explains that "We don’t ask any questions about desire." – the term "desired," which seems foreign in relation to Divinity, clarifies that it is a will that transcends all understanding).
More than anything else, the sanctification of the mundane creates a place for God within the very fabric of the world – the realization of the purpose of "a dwelling place in the lower realms."
In a similar manner, our sages used the same term of Divine desire in relation to another concept – "The Holy One, blessed be He, desires the prayers of Israel." Before discussing the connection between "a dwelling place in the lower realms" and prayer, it is worth mentioning that this connection is particularly evident in the month of Cheshvan: one of the expressions of concluding the holidays and returning to daily life is the halachic ruling that on the 7th of Cheshvan, prayers for rain commence. The reason for this ruling is that during Sukkot, all Jews were in the Temple in Jerusalem, and over the fifteen days until the 7th of Cheshvan, they would make their way back home. Only when the last Jew in the Land of Israel reached his home, with no fear that the rains "will intercept him on the way," do we start praying for rain. The return from the peak of holiness to mundane reality is expressed in the beginning of the prayer for rain. (The Baal Shem Tov explained the wording "Who causes the wind to blow and the rain to fall" as referring to returning the spirituality of the festivals back up to Heaven and the drawing down of material abundance into the world).
The prayer for rain is the most straightforward expression of prayer – the plea of the inhabitants of the land to receive their basic needs from the heavens. Therefore, the prayer for rain encompasses all the blessings that a person requires – physical-material needs, human-social needs, and the spiritual need for a connection with God [alluded to by the fact that the Hebrew letters of גשם (rain) are the initials of all God's blessings – "And I will give your גשם (rains) in their time," "And I will give שלום (peace) in the land," and "And I will place משכני (My dwelling) in your midst"].
The Praying Person
What is the connection between the preparation of the world for the presence of God ("a dwelling place in the lower realms"), and prayer? "A dwelling place in the lower realms" doesn't imply a physical space for God, as "The whole earth is filled with His glory" and "I fill the heavens and the earth." God is not defined in terms of place and time. "A dwelling place in the lower realms" means that God becomes inwardly and constantly present within the consciousness of the world – human consciousness.
The Torah describes how before the creation of humanity, all of reality was in a state of "standby." The plants did not grow, for there was no rain. And the rain did not fall, for “there was no man to work the earth.”  Man, who would recognize the blessing of rain and pray for it, was not yet created. Creation began to fulfill its purpose only when it received the awareness of the praying human (and there's an allusion: If the word אדם (Adam) is spelled out if full אלף-דלת-למד, it is a permutation of the words אדם מתפלל )the praying person). Just as the presence of God within mundane reality transforms the world itself into a place for God, similarly, prayer is an appeal to God within the very "I" of the human, for all his needs, troubles, joys, and hopes. When a person studies Torah or fulfills commandments, he removes his thoughts from his personal existence and focuses on understanding and fulfilling the will of his Creator. In prayer, however, a person stands – as is – before his God.
Engaging in Torah study or observing commandments is vital. Without them, a situation can arise in which a person acts negatively or wrongly during prayer. For example, the Talmud tells of a thief who prays for success in his theft. On the other hand, though, we should not enter a situation in which our engagement in God’s directives makes us forget our essential state of standing before Him and calling out to Him in all situations in our lives – including the difficult and negative situations.
Indeed, the phrase "In all your ways, know Him" is interpreted by our sages to include "even for the sake of transgression!" One interpretation is that even when a person succumbs to his evil inclination and sins, he still should pray and cry out to God. The verse's conclusion, "and He will straighten your paths," indicates that through "In all your ways, know Him," the sinner’s consistent and persistent calling out to God, even in the hardest and darkest moments, God will ultimately straighten his path and bring him back to goodness.
The service of "In all your ways, know Him" in this manner, in which every day, every moment, in every situation and from every place, we pray to God and seek to know Him, makes it possible for us to sanctify all the mundane matters of life.
 Pirkei Avot 2:8.
 Proverbs 3:6.
 Tanya Ch. 36.
 Yevamot 64a.
 The Silent Prayer.
 Isaiah 6:3.
 Jeremiah 23:24.
 Genesis 2:5.
 Proverbs 3:6.