The Messenger of Allah (s.a.w.a.) informed: Hasan was named al-Hasan (from Mohsin – Beneficence) because Allah kept the skies from falling on earth with His Beneficence. Ali and Hasan are both names which are derived from Allah’s names, and Husain is a derivative of Hasan. (The Imams represent Allah’s virtues and one of Allah’s virtues is ‘Beneficence’. Imam Hasan (a.s.) represents Allah’s Beneficence. Imam Hasan is the reason that the skies do not fall to the earth. Refer Ziyarat Al-Jamea Al-Kabeerah.)
Behaar al-Anwaar v 43 p 252 Al-Manaaqeb v 3 p 166