“Once I asked him (a.s.) if the two angels know the sin or good deed that a servant (of Allah) may intend to perform. The Imam said, ‘Are the smell of a trash collection site and a sweet smelling substance the same?’ I said, ‘No, they are not the same.’ The Imam said, ‘Whenever a servant (of Allah) intends to perform a good deed his breath comes out with a good smell and the angel on the right side says to the one on the left side, ‘Stand up; he intends to perform a good deed.’ When he performs it his tongue serves as his pen and his saliva as ink and he writes it down for him. Whenever he intends to commit an evil deed his breath comes out with a foul smell. The angel on the left says to the one on the right, ‘Stop; he intends to commit an evil deed.’ For an evil act his tongue serves as the pen and his saliva as ink and he writes it down against him.’”