If you then ask, “How can the jurisprudents approve the fasting of a person who confines himself to restraining the appetite of his stomach and the urge of his sex instinct, but neglects these inward aspects of the fast; how, then, can they say that his fast is valid?” Then know that the jurisprudents of the outward law support its formal requirements by means of proofs far weaker than those with which we established its inward conditions, especially those of backbiting and the like. At any rate, the jurisprudents of the outward law are not expected to concern themselves with any obligations other than those which are within the reach of the ordinary common folk who are occupied with the affairs of this world.
On the other hand, the learned men of the hereafter mean by validity acceptance and by acceptance the achievement of the intended purpose. By the purpose intended in fasting they understood the taking over of one of the qualities of God, namely, endurance (ṣamadiyya) as well as following in the example of the angels by refraining, as much as possible, from carnal lust while man, by virtue of his ability to overcome lust through the light of reason, stands above the animals [which possess no such light]. On the other hand, because he is subject to carnal lust and is judged by his ability to fight [its temptations]. The more he indulges in lust the lower he descends and the closer he comes to the level of the animals. The more he suppresses his lust the higher he ascends and the closer he comes to the level of the angels. The angels stand in close proximity to God, and whoever follows in their footsteps and emulates their example draws like them near to God. But this proximity (qurb) is not one of location but one of qualities and attributes.
If, among the men of insight and the physicians of the heart, this be the secret of fasting, what good-will there be in delaying a meal and combining two at sunset while indulging in the satisfaction of all the other physical desires and lusts throughout the day? And if there were good in such a behavior what would these words of the Messenger, God bless him and grant him peace, mean, “How often a man gets nothing out of his fast except hunger and thirst” (Ibn Māja, ṣiyām)? For this reason Abū ad-Dardā’ once said, “How good is the sleep of the wise men and how excellent is their eating; behold how they put to shame the wakefulness of the foolish and their fasting. Verily the weight of an atom of the worship of the faithful and pious is better than the weight of mountains of the worship of those who are misguided (and those in error).” Consequently, one of the learned men said, “How often a fasting man is not truly fasting, and how often a man not abstaining from food and drink is truly fasting.” The man who is truly fasting while not abstaining from food and drink is he who keeps himself free from sin; and the fasting man who is not truly fasting is he who, while he hungers and thirsts, allows himself every freedom in sin.
But everyone who truly understands fasting and its secret knows that he who abstains from food, drink, and sexual intercourse but commits [all manner of] sins is like the person who, in performing the ablution runs his hand over one of his members thrice, thereby outwardly fulfilling the Law as far as the member is concerned, but neglecting the truly important thing which is the actual washing. Consequently, because of his ignorance, his prayer is rejected. On the other hand, he who breaks the fast through eating but observes it by keeping himself free from sin is like the person who, in performing the ablution, washes each of the members of his body once only. His prayers are, by the will of God, accepted because he has fulfilled the principal thing in the ablution, although he has failed to fulfill the details. But he who does both is like the person who, in performing the ablution, washes each member of his body thrice, thereby fulfilling both the principal purpose of ablution as well as its elaborate details, which constitutes perfection. The Messenger, God bless him and grant him peace, once said, ‘‘Verily fasting is a trust; let each, therefore, take good care of his trust” (al-Kharā’iṭī). And when he recited, ‘‘Verily, God commands you to deliver trusts to those entitled to them.” (an-Nisā’:58), he raised his hands and touching his ears and eyes said, “[The gift of] hearing and [the gift of] seeing are each a trust [from God].” Similarly [the gift of speech is a trust], for if it were not so the Messenger, God bless him and grant him peace, would not have said, “If anyone disputes with another and swears at him let the latter say, ‘I am fasting, verily I am fasting’” (al-Bukhārī, ṣawm). In other words: ‘My tongue has been entrusted to my care, so how can I release it to answer your insults?”
It therefore becomes clear that every act of worship is possessed of an outward form and an inner [secret], an external husk and internal pith. The husks are of different grades and each grade has different layers. It is for you to choose whether to be content with the husk or join the company of the wise and the learned.