Bismillah al-Rahman al-Rahim
“All the works of the children of Adam are theirs, except fasting. It belongs to Me, and I will reward them for it.” (Hadith Qudsi)
Our worship and our actions are often touched with association (shirk), even though this association is not a theological or conscious association - it is an association arising out of the fact that our desires, our agendas, our wishes, our biases are intermixed with our worship. When the nafs (in its lower states) is active, it impinges upon, touches, and colors everything we do - our worship as well as our actions.
When fasting we hold back our nafs and thus our worship is (potentially) lifted, it rises beyond our day to day worship, beyond the intermingling with the lower nafs. So we are commanded to make this month a month specifically devoted to worship, a movement towards seeking the elevation of our worship beyond its usual limits, beyond the narrow, earthbound, self-limiting world of the nafs. So we enter into an exchange with God - our supplication to Him and His call to us.
“....I answer the prayer of the suppliant when he calls on Me, so they should answer My call and trust in Me that they may walk in the right way.” (Qur'an 2:186)
All this is possible through the unconditional acceptance of the command and invitation of God to fast. Through carrying out this command, the nafs comes to know that it is ruled by something beyond itself, that there is a higher self that is guardian and owner and governor over the nafs and its appetites and over the physical form and its needs.
And the self which governs, in turn, has only acquired this beneficial power and control because it has responded to a higher governance: the teaching command of the One who ordained the fast and proclaimed its momentousness: “....and that you fast is far better for you, if you did but know....” (Qur'an 2:184)
So the fast teaches that there is a self that stands beyond and above the conglomeration of attributes that comprise a person - that is the self capable of truly bowing before God - and that is the centre around which the other attributes should circumambulate.
Your body and nafs submit to you - you submit to God. Through God's command you shape your nafs and through your seeking His commands, He shapes you.
“...Then He proportions you, then balances you....” (Qur'an 82:7)