‘‘The Fast (Sawm) is for Me and I will reward it.’’ 
This connection is enough to show the high status of fasting. Similarly, the Ka’bah is highly dignified due to its close connection to Him, as occurs in His statement:
‘‘And sanctify My House.’’ 
Indeed, the fast is only virtuous due to two significant concepts:
THE FIRST: It is a secret and hidden action, thus, no one from the creation is able to see it Therefore riyaa‘ (showing off) cannot enter into it.
THE SECOND: It is a means of subjugating the enemies of Allaah. This is because the road that the enemies (of Allaah) embark upon (in order to misguide the Son of Aadam) is that of desires. And eating and drinking strengthens the desires. There are many reports that indicate the merits of fasting, and they are well known
THE RECOMMENDED ACTS OF FASTING:
The pre-dawn meal (suhoor) and delaying in taking it are preferable, as well as hastening to break the fast and doing so with dates. Generosity in giving is also recommended during Ramadhaan, as well as doing good deeds and increasing in charity. This is in accordance with the way of the Messenger of Allaah. It is also recommended to study the Qur‘aan and perform I‘tikaaf (seclusion for worship) during Ramadhaan, especially in its last ten days, as well as increasing upon the exertion (towards doing good deeds) in it. In the two Saheehs, ’Aa‘ishah said: ‘‘When the last ten days (of Ramadhaan) would come, the Prophet would tighten his waist wrapper (izaar)’’  The scholars have mentioned two views concerning the meaning of ‘tighten his wrapper (izaar)’ The first is that it means the turning away from women. The second is that it is an expression denoting his eagerness and diligence in doing good deed. They also say that the reason for: the last ten days of Ramadhaan was due to his seeking of the Night of al-Qadr (Laylatul-Qadr).
AN EXPLANATION OF THE INNER SECRETS OF FASTING AND ITS CHARACTERISITCS:
There are three levels of fasting, the general fast, the specific fast and the more specific fast. As for the general fast, then it is the refraining of ones stomach and their private parts from fulfilling their desires. The specific fast is the refraining of ones gaze, tongue, hands, feet, hearing and eyes, as well as the rest of his body parts from committing sinful acts. As for the more specific fast, then it is the heart’s abstention from its yearning after the worldly affairs and the thoughts which distance one away from Allaah, as well as its (the heart’s) abstention. From all the things that Allaah has placed on the same level.  From the characteristics of the specific fast is that one lowers his gaze and safeguards his tongue from the repulsive speech that is forbidden, disliked, or which has no benefit, as well as controlling the rest of his body parts. . In a hadeeth by al-Bukhaaree: ‘‘Whosoever does not abandon false speech and the acting upon it, Allaah is not in need off his food and drink.’’ 
Another characteristic of the specific fast is that one does not overfill himself with food during the night. Instead, he eats in due measure, for indeed, the son of Aadam does not fill a vessel more evil than his stomach. If he were to eat his fill during the first part of the night, he would not make good use of himself for the remainder of the night. In the same way, if he eats to his fill for suhoor, he does make good use of himself until the afternoon. This is because excessive eating breads laziness and lethargy therefore, the objective of fasting disappears due to one’s excessiveness in eating, for what is indeed intended by the fast, is that one savours the taste of hunger and becomes an abandoner of desires.
As for the recommended fasts, then know that preference for fasting is established in certain virtuous days. Some of these virtuous days happen every year, such as fasting the first six days of Shawwaal after Ramadhaan, fasting the day of ’Arafah, the day of ’Ashooraa, and the ten days of Dhul-Hijjah and Muharram. Some of them occur every month, such as the first part of the month, the middle part of it, and the last part of it. So whoever fasts the first part of it, the middle part of it and the last part of it, then he has done well. Some fasts occur every week, and they are every Monday and Thursday. The most virtuous of the recommended fasts is the fast of Daawood. He would fast one day and break his fast the next day. This achieves the following three objectives, the soul is given its share on the day the fast is broken. And on the day of fasting, it completes its share in full. The day of eating is the day of giving thanks and the day of fasting is the day of having patience. And Faith (eemaan) is divided into two halves- that of thankfulness and that of patience.  It is the most difficult struggle for the soul. This is because every time the soul gets accustomed to a certain condition, it transfers itself that. As for fasting every day, then it has been reported by Muslim, from the hadeeth of Aboo Qataadah that ’Umar (radiyallaahu ’anhu) asked the Prophet (sallallaahu ’alayhi wa sallam): What is the case if one were to fast everyday? So he (sallallaahu ’alayhi wa sallam) said: ‘‘He did not fast nor did he break his fast or, he did not fast and he did not break his fast.’’  This is concerning the one who fasts continuously, even during the days in which fasting is forbidden.
CHARACTERISITCS OF THE MORE SPECIFIC FASTS:
Know that the one who has been given intellect, knows the objective behind fasting. Therefore, he burdens himself to the extent that he will not be unable to do that which is more beneficial than it. Ibn Mas’ood would fast very little and it is reported that he used to say: ‘‘When I fast, I grow weak in my prayer. And I prefer the prayer over the (optional) fast.’’ Some of the Companions would weaken in their recitation of the Qur‘aan when fasting. Thus, they would exceed in breaking their fast (i.e.. by observing less optional fasts), until they were able to balance their recitation. Every individual is knowledgeable of his condition and of what will rectify it.