Quran

This verse indicates that the basic rule on things and food is that they are permissible, and that if there is no Sharia text to indicate that a thing is prohibited, then it remains permissible. Whatever Allah has remained silent about is permissible, because Allah has detailed that which is prohibited. If He has not clearly declared it to be prohibited, then it is not prohibited. Al-Saadi: 271.
Question: How do we infer from this verse this basic rule: All things remain permissible except what is declared to be prohibited ?

This applies to anyone who follows a passion or an ecstasy without guidance from Allah, whether it is out of love or hatred. One must not follow whatever he loves as a religious act nor calls others to it. Moreover, when one does not like something, he must not take this hatred as a religious act and forbids others from it, unless it is led by Allah's guidance which is His Sharia (divine law) that He ordained to His Messenger (ﷺ). Therefore, whoever follows his whim out of love or hatred for something without guidance from Sharia, then he is following his desire without guidance from Allah. Ibn Taimyah: 3/96.
Question: Explain the risk of following one's own whims without Allah's guidance?

Allah Has made clear that their misguidance is the worst of its kind since it is driven by whims and not by reason and reflection. (Without any knowledge), which means without reason. Ibn Atiyah:2/339.
Question: What is the worst kind of misguidance?

The individual does not fully give up sin, either outward or hidden, until he learns what it is and finds out about it. Finding out about it and learning what constitutes sin, both outward or hidden, so that one is aware of it, is an individual obligation for everyone who is accountable. Many people are unaware of many sins, especially the sins of the heart such as arrogance, self-admiration, showing off and so on, to such an extent that a person may commit many of these sins without being aware of them, because of lack of knowledge and understanding. Al-Saadi: 271.
Question: For an individual, what is first thing to do to avoid committing outward and hidden sins?

(And avoid committing sin, whether openly or in secret), this includes all sins since they are all committed either openly or in secret. It is said that (openly) refers to sinful actions while (in secret) refers to sinful beliefs. Ibn Juzay: 1/284.
Question: This verse employs a concise style to convey general meanings. Explain.

This verse indicates that inspirations and spiritual revelations, a phenomenon that is particularly spread among Sufis and their ilk, is not to be regarded as truth on its own, and should not be accepted until it has been checked against the Book of Allah and the Sunnah of His Messenger (ﷺ). If the Quran and Sunnah testify in its favor, then it may be accepted, but if it is contrary to them, then it is to be rejected. If the evidence is absent, then judgement is to be reserved and it is to be neither accepted nor rejected because revelation and inspiration may come from the Most Merciful, or it may come from the devil, so it is essential to distinguish between the two and to see the difference between them. Failing to see the difference between them leads to errors and misguidance the extent of which can only be known by Allah. Al-Saadi: 271.
Question: Using this verse, how do you respond to one who accepts inspirations and spiritual revelations without having them checked against the Quran and Sunnah?

(Thus We have placed in every city the greatest), just like we placed in Makkah its greatest criminals, we had done the same in every city. The greatest criminals were mentioned because the rest of the criminals follow them. Ibn Juzay: 1/284.
Question: The verse mentions only the greatest criminals. Why?