To be more specific, I would give a few concrete instances of the explanations of the Holy Book given to us by the Holy Prophet (SAWS). These examples will also show the drastic amount of what we lose if we ignore the Sunnah of the Holy Prophet (SAWS):
1. The Salah (prayer) is the well-known way of worship which is undisputedly held as the first pillar of Islam after having faith. The Holy Quran has ordered more than 73 times to observe it. Despite this large number of verses giving direct command to observe the Salah, there is no verse in the entire Book to explain how to perform and observe it.
Some components of the Salah, like ruku’ (bowing down) or sujud (Prostration) or Qiyam (standing) are no doubt, mentioned in the Holy Quran. But the complete way to perform Salah as a composite whole has never been explained. It is only through the Sunnah of the Holy Prophet (SAWS) that we learn the exact way to perform it. If the Sunnah is ignored, all these details about the correct way of observing Salah are totally lost. Not only this, nobody can bring forth an alternate way to perform Salah on the basis of the Holy Quran alone.
It is significant that the Holy Quran has repeated the command of observing Salah as many as 73 times, yet, it has elected not to describe the way it had to be performed. This is not without some wisdom behind it. The point that seems to have been made deliberately is one of the significance of the Sunnah.
By avoiding the details about no less a pillar of Islam than Salah, it is pointed out that the Holy Quran is meant for giving the fundamental principles only. The details are left to the explanations of the Holy Prophet (SAWS).
2. Moreover, it is mentioned in the Holy Quran that the ‘Salah’ is tied up with some prescribed times. Allah Almighty says:
“Surely, the Salah is a timed obligation for the believers.” (4: 104)
It is clear from this verse that there are some particular times in which the Salah should be performed. But what are those times is nowhere mentioned in the Holy Quran. Even that the daily obligatory prayers are five in number is never disclosed in the Holy Book. It is only through the Sunnah of the Holy Prophet (SAWS) that we have learnt the exact number and the specific times of the obligatory prayers.
3. The same is the position of the number of Rak’at to be performed in each prayer. It is not mentioned anywhere in the Holy Quran that the number of Rak’at is two in Fajr, four in Zuhr, Asr and Isha; it is only in the Sunnah that these matters are mentioned.
If the Sunnah is not believed, all these necessary details even about the first pillar of Islam remain totally unknown, so as to render the Salah too vague an obligation to be carried out in practice.
4. The same is the case of Zakah (alms giving), the second pillar of Islam, which is in most cases combined with the Salah in the Holy Quran. The order to ‘pay Zakah’ is found in the Holy Book in more than thirty places. But who is liable to pay it? On what rate it should be paid? What assets are liable to the obligation of Zakah? What assets are exempted from it? All these questions remain unanswered if the Sunnah of the Holy Prophet (SAWS) is ignored. It is the Holy Prophet (SAWS) who explained all these details about Zakah.
5. Fasts of Ramadan are held to be the third pillar of Islam. Here again only the fundamental principles are found in the Holy Quran. Most of the necessary details have been left to the explanation of the Holy Prophet (SAWS), which he disclosed through his sayings and acts. What acts, other than eating, drinking and having sex, are prohibited or permitted during the fast? Under what conditions can one break the fast during the day? What kind of treatment can be undertaken in the state of fasting? All these and similar other details are mentioned by the Holy Prophet (SAWS).
6. The Holy Quran has said after mentioning how to perform wudu, (ablution):
“And if you are junub (defiled) well-purify yourself.” (5:6)
It is also clarified in the Holy Quran that while being junub (defiled) one should not perform prayers (4:43). But the definition of junub (defiled) is not given anywhere in the Holy Quran nor is it mentioned how should a defiled person ‘well-purify’ himself. It is the Holy Prophet (SAWS) who has explained all these questions and laid down the detailed injunctions on the subject.
7. The command of the Holy Quran concerning Hajj, the fourth pillar of Islam, is in the following words:
“And as a right of Allah, it is obligatory on people to perform the Hajj of the House – whoever has the ability to manage his way to it.” (3: 97)
It is just not disclosed here as to how many times the Hajj (pilgrimage to Makkah) is obligatory? The Holy Prophet (SAWS) explained that the obligation is discharged by performing Hajj only once in a life-time.
8. The Holy Quran says:
“Those who accumulate gold and silver and do not spend them in the way of Allah, give them the good news of a painful punishment.” (9:34)
Here, ‘accumulation’ is prohibited and ‘spending’ is enjoined. But the quantum of none of the two is explained. Upto what limit can one save his money, and how much spending is obligatory? Both the questions are left to the explanation of the Holy Prophet (SAWS) who has laid down the detailed rules in this respect.
9. The Holy Quran, while describing the list of the women of prohibited degree, with whom one cannot marry, has extended the prohibition to marrying two sisters in one time:
“And (it is also prohibited) to combine two sisters together.” (4:23)
The Holy Prophet (SAWS) while explaining this verse, clarified that the prohibition is not restricted to two sisters only. The verse has, instead, laid down a principle which includes the prohibition of combining an aunt and her niece, paternal or maternal, as well.
10. The Holy Quran says:
“Today the good things have been permitted to you.” (5:5)
Here ‘the good things’ are not explained. The detailed list of the lawful ‘good things’ has only been given by the Holy Prophet (SAWS). He has described different kinds of food being unlawful for the Muslims and not falling in the category of ‘good things’. Had there been no such explanation given by the Holy Prophet (SAWS) everybody could interpret the ‘good things’ according to his own personal desires, and the very purpose of the revelation, namely, to draw a clear distinction between good and bad, could have been disturbed. If everybody was free to determine what is good and what is bad, neither any revelation nor a messenger was called for. It was through both the Holy Book and the Messenger that the need was fulfilled.
Numerous other examples of this nature may be cited. But the few examples given above are, perhaps, quite sufficient to show the nature of the explanations given by the Holy Prophet (SAWS) as well as to establish their necessity in the framework of an Islamic life ordained by the Holy Quran for its followers.