From the moment that a person has a thought to do something good—Miyad she'oleh ra'ayon la'adam la'asot mitzvah (commandment). The minute a person has a thought in his mind, “I want to do something good.” It creates an impact in heaven, in shamayim (heaven), u'mamshich miShamayim or makif. And Hashem gives this person literally a light that surrounds him.
And this great, incredible holiness—all he did was have a thought. He had a thought to do a mitzvah, and he already has this holiness. It's on top of him and surrounding him. The minute you make a decision to do a mitzvah, the minute you make a decision to do something good, there's already a holiness surrounding you. That's what the Pasuk (verse) says: “You should become holy and you'll be holy.” What does it mean, you should become holy? Once you become holy, you make a decision for holiness, you make a decision for kedushah (holiness), all of a sudden, it starts to surround you. You got it. It's around you. And all of a sudden, it is lifting you up.
That's why, when we make a Beracha (blessing) on a mitzvah, we say, asher kid'shanu (Who sanctified us), once I decided to do this. I have not yet done the mitzvah. Almost every Beracha on the mitzvah is prior to the mitzvah. You didn't yet do anything. But you were already sanctified because of the thought. That's what momentum means. Momentum means that once you decide to do something, you have more power than you had five minutes ago. You have more capability than you had five minutes ago. And now all of a sudden, there's a kedushah, there's a momentum. And then once you do that good thing, you do that mitzvah, there's more kedushah, there's more momentum.
This is why women pray on Friday nights right after they lit the candles. Because they lit the candles, they did a mitzvah, there is now a momentum to bring holiness in their home, and now they ask Hashem, “I want more holiness in my home.” Because you just started to create a momentum. And this is why most people can't see it, because people think that if I am standing here and I'm going to decide to do that, it's me doing that. So they think I could do one, two, three things. They really can't see that far ahead, and I'll explain more in a minute. What we don't realize is that once you take step one, you're now a new person because you have a new momentum, and once you take step two, you're a new person.