Quran

Meaning: When these disbelievers are afflicted with disease or hardship, they call upon their Lord, which means that they cry out to Him to remove the hardship, Him alone without association to the idols since they know that no relief would ever come from them. Al-Qurtubi: 16/433.
Question: Explain how Allah censures those who remember Him during adversity, and forget Him during prosperity.

Allah says, (when) for mercy, and says, (if) for evil, to indicate that He often decrees more good to them than evil. Ibn Juzay: 2/169.
Question: How can we infer from this verse that good things happen to people more often than evil?

Since adversities result from committing sins, Allah alerts them to that fact, and refutes their despair while not backing away from their sins for which they are punished: (For what their hands have put forth). Al-Biqai: 15/95.
Question: List some of the effects of sins.

(For what their hands have put forth), this is to point out that whatever afflicts them in worldly life is because of their deeds, which Allah made them a cause for painful effects that no one encompasses its subtleties except Allah. People have to reckon with themselves, evade the causes of these afflictions, and make up for what they had missed, for it will save them from evil and despair. This is a great etiquette of the revelation, where Allah says, (Whatever good happens to you is from Allah, but whatever bad happens to you is from yourself) [4:79]. Ibn Ashur: 21/101.
Question: What is the cause of calamities that strike mankind in this worldly life?

Al-Shaabi said: "This verse means that whoever provides a service to another seeking worldly gain, this gain will never increase with Allah." Al-Qurtubi: 16/438.
Question: Will the servant be rewarded for helping another for worldly gains only?

Glory be to the One Who brings blessings through His trials and tests, and Who bestows grace through His punishment. Otherwise, if He caused them to taste the consequences of all that they have earned. He would not leave any living creature on the face of the earth. Al-Saadi: 643.
Question: There is a blessing and bounty from Allah in trials. How?

Corruption in land is by drought trials, and akin to it. Corruption at sea is by drowning, less fish to catch, and depression of trade, etc. All corruption is due to disbelief and disobedience by the people. Ibn Juzay: 2/169.
Question: What are the signs of the appearance of corruption and its causes?