Hi Rabbi, thank you for your great site and all you do for everyone. As I pursue my learning of Torah I have repeatedly come across this topic called shmirat habrit, that seems to be of extreme severity, although I feel that I am unclear of the nature of this sin.If you would be able to enlighten me on this area of halakha, I would greatly appreciate it.
Shmirat habrit is an important halacha for men. The sin of wasting seed is a severe sin, especially if it is done on purpose. Aside for this a man has to be careful not to do things that can cause him to have improper thoughts. Therefore, a man may not gaze at women, involve himself in fantasies involving women, or anything else that will bring him to have such thoughts, in addition to the fact that these things can cause hm to lose seed.
On the other hand, often people get obsessed with shmiras habris, and end up thinking about these topics all the time. This is a ploy of the yetzer hora, dressed in very pious garb, keeping your mind on the topic. For example, if someone were to tell you don’t think about a purple elephant, don’t think about a purple elephant, again be extra careful not to think about purple elephants… what are you going to be thinking about… purple elephants! The Rambam Issurei Biah 22-21 gives us guidance how to avoid such thoughts; to think torah thoughts, as improper thoughts don’t come up when a person’s thought are involved in torah. Alternatively, if a person sees that he is having such thoughts, he can always switch his brain to think torah thoughts, a mussar idea, a Mishan, or anything else that is easy for you to think. R’ Volbe zt”l used to say that before a person walks out into the street, he should prepare a torah related topic to think about, this way even if there are improperly dressed women etc, it won’t affect him, or at least it’s effect will be diminished, as he is thinking in torah.
P.S. This doesn’t mean that a person can think in torah and not watch his eyes, rather both ideas should be used together.