Quran

The Arabic word used for (unlawful gains) is "Suht" which means: Ravage. It is called that because it ravages good deeds and wipes them out, or because it wipes out the dignity of the human being. Al-Qurtubi: 7/485.
Question: Why is unlawful gain called "Suht"?

This verse describes words that get into their ears and hearts, and food that gets into their mouths and stomachs. This represents feeding the hearts and bodies with the worst sustenance: Lies and Suht (unlawful gain). Ibn Taimyah: 2/475-476.
Question: The verse mentions two kinds of sustenance on which the Jews feed. What are they?

The rabbis (devoted servants of Allah) were the ones who guide people with knowledge gradually. Mujahid said: "Rabbis are higher than scholars." Al-Qurtubi: 7/495.
Question: How can a Muslim be a devoted servant of Allah?

(So do not fear people but fear Me, and do not trade My verses for a small price), for then you would be concealing the truth and making falsehood manifest for the sake of insignificant worldly gains. If the scholar is free of these faults, then that is by the help and guidance of Allah and His blessing, because He has focused on acquiring knowledge and teaching people, and he knows that Allah Has entrusted him with protecting the knowledge that He had given him, and be a witness thereto. So, he should fear only his Lord, and not let the fear of people prevent him from doing what is required of him or give precedence to worldly matters over religious matters. Furthermore, the sign of a scholar being doomed is that he is content to being idle and doing anything, and not caring about what he has been entrusted with. He neglects what he has been entrusted with, for he has sold his religious commitment for worldly gains. Al-Saadi: 233.
Question: In light of this verse, describe the difference between a devoted scholar and a non-devoted one?

A life for a life rule is applied, regardless of whether the killer is a chief of a tribe and his victim is a commoner; whether an old one vs a young one, a wealthy one vs a poor one, an Arab vs non-Arab or a Hashemite vs a Quraishi. All of this to negate what the people used to do during pre-Islam period. Ibn Taimyah: 2/482.
Question: Security cannot be achieved unless justice is applied to all people. Explain.

Allah makes the charitable waiving of legal retribution against the killer an expiation for the waiver, while implementing legal retribution is not an expiation for him. This indicates that waiving is better for him because the calamity expiates his sins, his patience is greatly rewarded, and he receives a higher rank with Allah. Ibn Taimyah: 2/481.
Question: Waiving is better than retribution. Explain in light of this verse.

For those who do not judge according to what Allah Has revealed, three different descriptions are used in accordance with three different standings. For their rejection, they are described as "disbelievers." For misplacing the rule of Allah, they are described as "wrongdoers." For deviating from the truth, they are described as "defiantly disobedient." Al-Alusi: 6/430.
Question: Allah describes those who do not judge according to His Sharia as disbelievers, wrongdoers and defiantly disobedient. Why?