The essence of the concepts of Ahl al-Sunnah.
How does the Qur'an explain everything?
Allah, the Almighty, says:
“And (bethink you of) the day when We raise in every nation a witness against them of their own folk, and We bring thee (Muhammad) as a witness against these. And We reveal the Scripture unto thee as an exposition of all things, and a guidance and a mercy and good tidings for those who have surrendered (to Allah).” (16:89)
This explanation encompasses the fundamentals of religion and its branches,
and the rulings of both this world and the Hereafter.
And all that people need.
As for the fundamentals of religion and the major issues of creed,
which the heart needs to constantly revisit and be reminded of,
they are repeated and reiterated in the Qur'an with multiple expressions and various proofs
so that they may settle in the hearts.
And some jurisprudential rulings are detailed in the Qur'an,
while others, along with some details of creed,
are sufficiently covered by their inclusion under the general principles and matters established by the verses of the Noble Qur'an.
And the Sunnah of the Messenger, peace and blessings of Allah be upon him, undertakes to detail them.
So, Allah the Almighty says:
“And (bethink you of) the day when We raise in every nation a witness against them of their own folk, and We bring thee (Muhammad) as a witness against these. And We reveal the Scripture unto thee as an exposition of all things, and a guidance and a mercy and good tidings for those who have surrendered (to Allah).” (16:89)
His saying, the Almighty, came after it:
“Lo! Allah enjoineth justice and kindness, and giving to kinsfolk, and forbiddeth lewdness and abomination and wickedness. He exhorteth you in order that ye may take heed.” (16:90)
“Lo! Allah enjoineth justice and kindness, and giving to kinsfolk, and forbiddeth lewdness and abomination and wickedness. He exhorteth you in order that ye may take heed.” (16:90)
that you may be reminded.
This is a verse that establishes a general principle:
that every matter involving justice and benevolence, or giving to relatives,
is among what the Qur'an commands.
And every matter involving indecency, wrongdoing, or oppression,
is among what the Qur'an prohibits.
Therefore, the intention is not that every specific detail of matters and their particulars is explicitly stated in the Noble Qur'an.
This is not logical,
because situations and events are constantly renewing and unending,
and thus cannot be confined between the covers of a book.
Rather, it is sufficient for them to be included under general verses.
For example, you will not find in the Qur'an a text that explicitly prohibits cigarettes and tobacco by name,
but you will find that covered by Allah the Almighty's saying:
“Those who follow the messenger, the Prophet who can neither read nor write, whom they will find described in the Torah and the Gospel (which are) with them. He will enjoin on them that which is right and forbid them that which is wrong. He will make lawful for them all good things and prohibit for them only the foul; and he will relieve them of their burden and the fetters that they used to wear. Then those who believe in him, and honour him, and help him, and follow the light which is sent down with him: they are the successful.” (7:157)
“Those who follow the messenger, the Prophet who can neither read nor write, whom they will find described in the Torah and the Gospel (which are) with them. He will enjoin on them that which is right and forbid them that which is wrong. He will make lawful for them all good things and prohibit for them only the foul; and he will relieve them of their burden and the fetters that they used to wear. Then those who believe in him, and honour him, and help him, and follow the light which is sent down with him: they are the successful.” (7:157)
“Those who follow the messenger, the Prophet who can neither read nor write, whom they will find described in the Torah and the Gospel (which are) with them. He will enjoin on them that which is right and forbid them that which is wrong. He will make lawful for them all good things and prohibit for them only the foul; and he will relieve them of their burden and the fetters that they used to wear. Then those who believe in him, and honour him, and help him, and follow the light which is sent down with him: they are the successful.” (7:157)
And there is no doubt that cigarettes are among the impure things (khaba'ith),
because they are harmful, so this verse is used as evidence for their prohibition.
Then, what is explained in the Sunnah falls under the explanation of the Qur'an.
For Allah the Almighty says:
“That which Allah giveth as spoil unto His messenger from the people of the townships, it is for Allah and His messenger and for the near of kin and the orphans and the needy and the wayfarer, that it become not a commodity between the rich among you. And whatsoever the messenger giveth you, take it. And whatsoever he forbiddeth, abstain (from it). And keep your duty to Allah. Lo! Allah is stern in reprisal.” (59:7)
So, disobeying the Messenger, peace and blessings of Allah be upon him, is disobeying the explanation of the Qur'an.
The essence of the concepts of Ahl al-Sunnah.