for when evil occurs, it attaches only to the created objects, not to the divine act itself.
Take, for example, a circumstance in which Allah decrees for a person something he dislikes. Undoubtedly, from that person’s perspective it is evil; yet the evil lies in the thing decreed, not in Allah’s decree, for the Almighty never decrees anything except for a profound wisdom—either for the individual concerned or for people at large.
At times that wisdom is particular to the one afflicted, and at times it serves humanity in general. If Allah decrees an adversity for someone and he meets it with patience and the hope of reward, he thereby gains good. And if Allah decrees a hardship for him that causes him to return to his Lord, the benefit is even greater; for when a person lives in constant ease he may forget to thank the Bestower and pay no heed to Allah, but when hardship strikes he remembers, repents, and turns back to his Lord—an immense benefit indeed.
As for others, the very matter that harms one individual may well profit them. Imagine a man whose house is built of clay bricks: Allah sends continuous, heavy rain. The owner suffers loss, yet the general population benefits from the rainfall. Thus what is evil for one person is good for others, and even for that individual its evil is only relative—harmful from one side but beneficial from another. It admonishes him and teaches him that the only refuge is Allah; there is no sanctuary except with Him. Consequently, he reaps a benefit far outweighing the damage he endured.
The point is that the author—may Allah have mercy on him—cited this ḥadīth in the chapter on patience because