Once, a female slave brought a beautiful flower, which had a wonderful fragrance and presented it to her master Imam al-Hasan al-Mujtaba(as). 

Imam(as) was so happy that he(as) instantly set her free. Anas bin Malik, who was present at the time, was surprised and remarked,

"Master! You have set her free for such a simple reason?

Indeed we do not see any connection between this flower and her freedom".

Thereupon, the Imam(as) said,

"Allah, the Almighty says in the Quran: ‘When you are greeted with a salute, greet with a better one than it, or return it’. (4:86).

She had expressed her feelings and it needed to be responded in a much better way, so I freed her". (Ahsanul-Muqaal).

Imam Ja’ffar as-Sadiq(as) has said,

"Al-Hasan bin Ali(as) was certainly the most true worshipper, ascetic and merited man among the people of his time".

It is reported that whenever al-Hasan(as) would perform ablution, he would tremble and his face turned pale.

When asked, he(as) said,

"It is only natural that one who stands in the presence of the Lord of the throne turns ashen and trembles." (Rawdhah al-Wa’idheen).

It is also reported that whenever al-Hasan(as) approached the door of Masjid (mosque), he would utter the following words:

"O Lord! Your guest is at your door. O Generous! The transgressor has come to You. Forgive my ugly deeds with Your generosity, O the most Generous". (Tabaqaat of Ibn Sa’d).