SHAFAQNA – Prophet Jesus/ Masih ibn Maryam/Isa ibn Maryam (AS) told his followers: Mosa ibn Imran commanded you to avoid adultery, but I recommend to you, do not even think about adultery, because the one who thinks about adultery is like a person who lit a fire in a room which has been painted beautifully. In this case, even though it is possible that the house may not burn in fire, but at the least the smoke will make the room black and ruins it [1]. Therefore, it is better that the human being avoids thinking about sins and improper sexual desires, as they can contaminate the soul and the thought, and can provide the basis for committing sins.
[1] Beharul Anwaar, Vol. 14, page 331.