July 10, 2026 Categories: Halacha & Hashkafa
Daf Yomi
A Saline Solution
“Its Soaking Is Its Laundering”
(Zevachim 94b)
What connection could there possibly be between soft and shiny contact lenses and the blood of sacrifices? The world of halacha includes every topic in the world – contact lenses and sacrifices actually have a common denominator in the realm of Jewish law.
Our sugya serves as a source for halachic foundations concerning cleaning items on Shabbos. The Gemara discusses the cleaning of skins spattered with the blood of kodashim, and subsequently expands on cleaning skins in general, on whether there is a difference between soft and hard hides, and on the halachos of cleaning them on Shabbos in particular.
As we know, one of the 39 av-melachos – principal labors performed in constructing the Mishkan (Sanctuary), and which one is forbidden to do on Shabbos – is melaben (whitening). The essence of this melacha is whitening and cleaning raw wool. The tolados (offspring or secondary acts) of the melacha include all types of laundering, such as soaking a garment in water as explained in our sugya, and are Biblically forbidden even without rubbing the garment.
Our Gemara asserts that all the above only applies to fabrics, but the halacha is different for leather garments (soft or hard), which may be soaked in water on Shabbos. The Gemara recounts that R. Chiya b. Ashi would splash Rav’s shoes with water to clean them on Shabbos, but that it is forbidden to rub leather garments, soft or hard (see Bi’ur Halacha, Orach Chayyim 302:9, s.v. Aval). Let us examine the reasons for distinguishing between leather and fabrics and the practical implications for the care of lenses on Shabbos.
Leather’s Properties
The reasons for distinguishing between leather and fabrics focus on the fact that fabrics are absorbent materials that soak up dirt or water which may clean them and therefore their soaking is considered part of laundering. On the other hand, leather does not absorb dirt or water in the same way. Some suggest that as leather absorbs very little, its soaking is not regarded as laundering since the leather is not really being laundered (just as one may rinse soiled eating utensils on Shabbos as the dirt is not absorbed in them). Possibly, though leather absorbs a little dirt or water, soaking it in water is not considered laundering because people are not accustomed to launder leather or because laundering it thus takes a lot of time and is not regarded as a regular method of cleaning. In any case, one must not rub leather because the prohibition of laundering does apply to leather. Only the halacha of “its soaking is its laundering” does not apply.Contact Lens Conundrum
If soaking leather is permitted on Shabbos, may we conclude that soaking contact lenses in cleaning fluid is also permitted? We must preface the discussion by saying that soft lenses do not resemble ordinary plastic. Though ordinary plastic does not absorb liquids, soft lenses do when exposed to air. Therefore, one may not squeeze out the liquids absorbed within. Additionally, it is forbidden to rub them with liquid as they are thereby cleaned, just as it is forbidden to rub leather. Furthermore, there may even be reason to forbid soaking lenses in cleaning fluid even if we assume that they resemble leather, which may be soaked, according to our sugya, in water. It could well be that leather is also forbidden to be soaked in a cleaning fluid for by so doing it becomes cleaned and whitened. The cleaning fluid of the lenses also removes the dirt that adheres to them.A Resolution
The solution for people with contact lenses is to soak them in saline, a fluid designed only to preserve the lenses without cleaning them. In this way, soaking the lenses resembles soaking leather in water, which is allowed on Shabbos. We emphasize that Rabbi Yosef Sholom Elyashiv rules that someone who wants to soak lenses in saline on Shabbos should clean them well before Shabbos. (Readers who want to expand their knowledge of the topic should refer to Orchos Shabbos, 13:37-40 and the remarks there, and Birurei Halacha 5.)
