Why is mercy attributed to Allah and evil attributed to people in verse 36 of Surat Ar-Rum?

This is out of good manners with Allah, for despite Him being the Creator, evil is not attributed to Him. This is why the Prophet, peace and blessings be upon him, said: "All good is in Your hands, and evil is not attributed to You." Everything Allah creates contains wisdom and benefit. Evil is not entirely absolute, but rather partial and relative. The calamities that befall people are due to their sins, as Allah Almighty said: "And whatever calamity befalls you, it is because of what your hands have earned."