Shulchan Aruch in Siman Kuf Samech Bet (section 162), Seif Bet (paragraph 2), describes the halakha (Jewish law) of how to do netilat yadayim (ritual handwashing). Most people have to do three times: one, two, three; one, two, three. I’m talking about netilat yadayim for food, of course, not the morning one. There’s a major difference between them. This is only for bread. Shulchan Aruch says that a person who does netilat yadayim has to pour three times.
What’s the reason for the three times? The first pouring is not really part of netilat yadayim; it’s to remove any dirt on the hands that would create a chatzitzah (barrier). The dirt is on the hands and in the water. Really, netilat yadayim starts with the second pouring. The first pouring is just to remove anything. Imagine people who worked on farms or in agriculture. They have dust and other things on their hands, so it’s not going to work. That’s why they first have to remove that.
Now, the problem is that if you had just a little bit of water for both hands, and you use some of it to remove the dirt, then you’re left with less than a revi'it (quarter-log measure) for netilat yadayim. That creates a problem. On one hand, you started with a revi'it, but the first pouring was to remove the dirt. So now you’re left with less than a revi'it for the actual netilat yadayim. How do you do that? Then he pours the water on his hand a second time, which is the first of the two pourings of netilat yadayim. These waters are now tamei (ritually impure), because if they take the tum'ah (ritual impurity) of the hands onto the water, then the water carries this tum'ah. Then he pours a third time in order to remove the mayim teme'im (impure water) and replace them with mayim tehorim (pure water).
The first one removes the dust. The second one is the netila, but now you have tum'at mayim (impurity of water). The third one removes the mayim teme'im from there. This is why we do netilat yadayim three times.
Now, I think I said it the right way when I said the problem is the first one. Let’s consider a scenario where my hands are not dirty. If my hands are not dirty, then the first time I’m pouring is during netilat yadayim. I don’t need the first one, so I could remove the first one, and I have two left. If I don’t need the first one because my hands are clean—I don’t work with cows; I work in an office, and my hands are perfectly clean—there is no chatzitzah. So if there is no chatzitzah, then I don’t need the first one; I go straight to the second one. It is the actual netila.
What was the problem? Why do I need these two steps, or why is the water becoming tamei? Isn’t the water metaher (purify)? How is the water becoming tamei? The only reason the water is becoming tamei is because of the first question I asked. The first time you do netilat yadayim, with the first pouring, you don’t have enough water after that, so the water is going to become tamei. But if you have a revi'it at the beginning, or if you pour a revi'it on top of your hands, the water doesn’t become tamei at all. This water stays tahor (ritually pure) forever. If you use less than a revi'it, the water will carry tum'ah. If you have a revi'it, the water will not carry tum'ah.
So really, the option of two pourings doesn’t exist. You either have three or you have one. You have three because you need the first one to remove the dust. Then you don’t have a revi'it, so you do one, and it carries tum'ah in the water; then you do the third one. Or my hands are clean. I have a revi'it. I pour a revi'it. I don’t need two, because if I use a revi'it, the water is not going to be tamei. If it’s not tamei, there’s no need to pour a second time. That’s exactly what Shulchan Aruch says: if the hands don’t have any dust or dirt, then you should pour the revi'it on both hands, or one revi'it and one revi'it.
We have a lot of water these days. You don’t need the first water because the hands are clean. You don’t need a second water either, because now you pour the revi'it. If you pour the revi'it, you don’t need to wash off the water that carries tum'ah. No, because that was only because you didn’t have a revi'it. If you have a revi'it, if you pour a revi'it, you don’t have such a thing. So you have two hands: either your hands are dirty and you need three times, or your hands are not dirty and you need one time with the revi'it. That’s it. That’s the halakha today. That’s what I do.
People are not noheg (customarily do) like that. People are noheg to do three times, al pi ha-sod (according to the esoteric tradition). Although it matches the halakha, I think it also comes from here: that’s what Shulchan Aruch writes. But you have to continue reading. You can’t read only the halakha. You have to continue reading. You can’t read only the halakha. That part, Shulchan Aruch says, if you use the revi'it, then one time is enough. That’s what I do to make a point. This is what you need to do: one and one. B'shefa (in abundance), you have a revi'it. By the way, a revi'it is small. But if you do it with a revi'it, there’s no problem. You need one time on each hand, and that’s enough.