Quran

Since mistakes are forgiven according to Sharia, it was thought that there was nothing against one who made a mistake; however, this is not true in the case of accidental killing in order to preserve lives, for it is a very serious matter. Allah says, sternly, urging to take all precautions when dealing with anything that causes death. (Must free), it is obligatory upon him to free (a slave), a person in slavery. Al-Biqai: 2/297.
Question: Allah prescribes expiation and blood money in the case of accidental killing even though this Muslim Ummah is forgiven for its mistakes. Why?

This confirms that this prohibition is very serious and that this action is diametrically opposed to faith. Indeed, such a thing can only be done by a disbeliever or an evil doer whose faith is sorely lacking, and for whom there is the fear of what is even worse than that. True faith prevents the believer from killing his brother with whom Allah has ordained the brotherhood of faith, which involves loving him, taking him as a close friend and ally, and protecting him from any harm; and what harm could be greater than killing? Al-Saadi: 192.
Question: Why a true believer would not kill a fellow believer?

This is a great approach toward understanding the laws of Sharia, namely that judgments are based on assumptions and appearances rather than on certainty and knowledge of the hidden. Al-Qurtubi: 7/51.
Question: This verse contains a great path toward understanding the laws of Sharia. What is it?

(Make sure) seek with prudence to clarify matters, verify its occurrence with accuracy, distinguish between the truth and falsehood, and act only on what is clear to you. (And do not say) words, let alone action against one (who offers you) no matter who he is, (the greetings of peace), he initiated the offer of peace while giving in, (You are not a believer). Al-Biqai: 2/299.
Question: A sign of a sincere and wise believer is his prudence and verification before taking action. Explain in light of this verse.

(Seeking), desperately pursuing through killing. (The perishable goods of worldly life): By taking his possessions of worldly life, or retaliating for an old blood feud. Ibn Abbas (t) said: "Some Muslim individuals caught up with a man who said to them: "Peace be upon you," but they killed him and took his possessions. Thereupon this verse was revealed: (...seeking the perishable goods of worldly life)". Al-Biqai: 2/299.
Question: The spoils of war are a test of the fighter in the cause of Allah. Explain in light of this verse.

This is a great education for one to feel for others when holding them accountable for situations in which he was before, such as a teacher harshly censures a student when the student spared no effort. Likewise, it is great education for those who, when evaluating students of knowledge, are used to being strict with them seeking out their mistakes. Ibn Ashur: 5/168.
Question: What education can one learn from this verse: (You were in the same position before)?

Meaning: Just as He guided you after you had been astray, He may also guide others; just as guidance was a gradual process for you, it may also be like that for others. So, the one who is perfect should look at his original imperfect state, and think about how he should deal with those who are still like that, on the basis of what he knows about how he was before, and he should call them with wisdom and beautiful preaching. This is one of the most effective ways in which he may benefit himself and others. Al-Saadi: 195.
Question: This verse contains a great rule for dealing with disobedient Muslims. Explain.