What is the exegesis of Allah Almighty's saying: "Indeed, Allah will not change the condition of a people until they change what is within themselves"?

The noble verse clarifies that Allah does not change the condition of a people, whether for good or ill, unless they change what is within themselves. If they were righteous and steadfast, and then changed their state to disobedience, Allah would punish them with hardships, barrenness, and disunity. He may also grant them a respite and lead them on gradually before seizing them suddenly. And if they were in evil, tribulation, and disobedience, and then repented and turned back [to Allah], Allah would change their condition to ease, blessings, unity of purpose, and righteousness of state. Thus, Allah does not change a blessing He has bestowed upon a people until they change what is within themselves. And if they were in a bad state and disobedient, and then became righteous, Allah would change their condition for the better.