What is the difference between reviling time, which is prohibited, and reviling the disbelievers, which is permissible in its proper context, and what is the secret behind this difference?

Cursing 'time' (ad-dahr) is absolutely forbidden because it is not deserving of curses. Allah is ad-dahr, meaning He is its Owner and Disposer. Cursing ad-dahr entails several corruptions: cursing that which is not deserving of curses, and the curse itself implies shirk (associating partners with Allah), and the cursing ultimately falls upon the Doer of these actions. As for disbelievers and their deities, they are deserving of curses, but we have been forbidden from confronting them by cursing their deities so that they do not curse Allah the Exalted. Therefore, it is not permissible to curse them if it is highly probable that it will lead to a greater harm. Otherwise, it is permissible when there is a need.