In accord with our purposes in this series we omit sections which are not directly relevant to our present theme (Shabbat eve in the home) or our modern circumstances. For this reason we move on to Section 161. I have edited paragraph 1 of this section because some of its elements are not only comparatively irrelevant to modern circumstances but also are intrusive and interrupt the flow of the argument. The phrases that I have edited out are concerned with the exact location under the nails of intrusive dirt (!) and a long additional note by Rabbi Moshe Isserles.
When a person bathes in a mikveh [a ritual bath], in order for the water to effect its purifying function it must come into direct contact with the person's skin. (I use the term 'purifying' because the ultimate purpose of the ritual bath is not cleanliness and hygiene, which are taken care of before entering the water, but a ritual purification with a spiritual meaning.) Thus anything extraneous which adheres to the body (such as a "band aid" or even matted hair) prevents the water from performing its purificatory function. Paragraph 1 of Section 161 seeks to do two things upon which we shall now elaborate.
First of all a general rule is established. Just as the ritual bathing in a mikveh has spiritual overtones so does the washing of the hands before eating bread. (We discussed this in Shabbat 035.) Therefore, as a general rule, anything adhering to the skin which would be considered as constituting a barrier when bathing in a mikveh must be considered as a barrier when performing netilat yadayyim as well. In a note which he appends to the end of this paragraph, and which I have omitted in the translation for the sake of clarity, Rabbi Moshe Isserles states that "there are some halakhic authorities who hold that the problem of barriers does not apply to netilat yadayyim" but he immediately adds that "the accepted rule follows the former opinion" - that of Rabbi Yosef Karo, as enunciated at the beginning of paragraph 1. That opinion is, of course, that "anything that is a barrier regarding bathing in a ritual bath is a barrier for netilat yadayyim."
The other matter which concerns us in paragraph 1 gives some examples of what might be considered a barrier when performing netilat yadayyim. Strictly speaking one must keep one's nails clean because dirt clinging to the skin underneath the nail could constitute a barrier and invalidate the hand-washing. The same consideration must apply to dough which has become caught under the nails while kneading the bread. In modern times a "band aid" or bandage that adheres to the skin constitutes a barrier because we cannot presume that the water will reach the skin underneath. Craftsmen and workers are liable to have specific kinds of dirt adhering to their fingers. Examples given are people who make wine: they will find the lees stick to their fingers; construction workers and other crafts people will find mud and cement under their nails - and so forth.
However, if the amount of 'specialized' dirt is so minimal that the craftsman involved would not usually consider it a bother it does not constitute a barrier for the purposes of netilat yadayyim. (However, if the dirt covers the majority of the hand it does constitute a barrier even if the workman could not care less about it.) We shall elaborate on this matter in the next shiur.
Other considerations as to what does and does not constitute a barrier in the case of netilat yadayyim are brought in the later paragraphs of Section 161, and they will be the subject of our next shiur. Today's shiur is a short one for reasons we may consider to be 'pedagogic': the remaining paragraphs of Section 161 form a unit and should not be separated, but to append them to this shiur would make the lesson too long. Therefore, this subject is
To be continued.