"I said to Abu Abdullah (Imam Jafar ibn Muhammad Al-Sadiq (as)): 'Inform me about optional fasting and about fasting on these three days. If I become in a state of janabah (major ritual impurity) at the beginning of the night and I know that I am in such a state but I deliberately sleep until dawn breaks, should I fast or not?' Imam (as) said: 'Fast.'"