Al-Hasan bin Mas’oud said, “One day, I went to Abul Hasan Ali bin Muhammad (a.s.) after my finger was scratched, and a rider knocked against my shoulder, and I went into a crowd that some of my clothes were torn. I said: may Allah save me from your evil O day! How ill-omened you are!’
Abul Hasan (a.s.) said to me, ‘O Hasan, you say so though you frequent us! You throw your guilt on that which is guiltless!’
I recovered my senses, understood my mistake, and said: I ask Allah to forgive me.’
Abul Hasan (a.s.) said, ‘O Hasan, what is the guilt of days that you are pessimistic at when you are punished for your deeds on them?’
I said, ‘I always ask Allah for forgiveness. It is my repentance O son of the messenger of Allah.’
He said, ‘By Allah, it does not benefit you. Allah punishes you for blaming days which have no guilt in what you blame them for. O Hasan, do you know that it is Allah Who rewards and punishes for deeds whether sooner or later?’
I said, ‘O yes, my master.’
He said, ‘Do not give days a role in the judgment of Allah!’
I said, ‘O yes, my master.”
Imam al-Hadi (a.s.) confirmed what the Prophet (a.s.) had announced in one of his traditions that it was not from Islam that a Muslim be pessimistic, but he must have a strong will and determination in doing everything except sins. ( Tuhaf al-Uqul, p.482-483. )
Reference : The Life of Imam ALI bin Muhammad AL-HADI