Imam Hasan (a.s.), like all other Imams was granted divine knowledge by Allah (swt) and he demonstrated it right from his childhood.
Once Imam Hasan (a.s.) was asked "What are the 10 strong things that are stronger than one another?" Imam Hasan (a.s.) replied:
Among the strong things is Stone;
Even stronger is the Iron which is used to break Stone;
Even stronger is the Fire which melts Iron;
Even stronger is the Water which extinguishes Fire;
Even stronger are Clouds that carry Water with them;
Even stronger is the Air which floats the Clouds with it;
Even stronger is the Angel who moves the Air;
Even stronger is the Angel who will give Death to the Angel who moves the Air;
Even stronger is the Death which will come upon the Angel of Death; and
Even stronger is the order of Allah (swt) which governs
Source: Chennai Shia Youth Association