Time is a tyrannical force. الدَّهْرُ أرْوَدُ مُسْتَبِدٌ.

Meaning, it is gentle in its dealings and dominant in its course. This is like the saying of Ibn Muqbil: "If time were to break me once, it would be for the sake of decay... for time is tyrannical towards peoples, full of change." "Arwad" means: it works its work silently, without being noticed. It is also said: tyrannica
l, determined in its course, and does not turn back.
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The proverb "Time is a tyrant" means that time works slowly and deliberately, but its will is absolute and unstoppable; it changes circumstances slowly and steadily until it achieves its purpose.
The closest English proverbs and expressions to this meaning are:
Time takes its toll.
Time will have its way.
Time and tide wait for no man.
The mills of God grind slowly, but exceedingly fine.
Time is the master of us all.
Time is the master of all. The closest English proverb that captures the essence of slowness, steadfastness, and influence is:
The mills of God grind slowly, but exceedingly fine.
However, if one wishes to express the irresistible power of time directly, the most fitting expression is:
Time will have its way.
That is, time has its own way, and nothing can stop it.
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أي لَيِّنُ المعاملة غالبٌ على أمره، وهذا كقول ابن مُقْبل:
إنْ يَنْقُضِ الدَّهْرُ مِني مرَّةً لِبلى ... فالدهر أرْوَدُ بالأقْوَامِ ذُو غِيَرِ
أرود: أي يعمل عملَه في سكون لا يشعر به، ويقال: المستبد الماضي في أمره لا يرجع عنه.