49
Question
By the way, you write that "if you have a thicker cream, you are not allowed to smear it on on Shabbos". Some permit using thicker creams on Shabbos in certain circumstances (see Shemirat Shabbat Kihilchata, 33, comment 64) All the best.
Can you comment further on this general concept of not using thick cream on Shabbos. What is the Melacha that can possibly be violated? Is it a DeOraysah?
Answer
This is what the Peninei Halacha (shabbat, 14, 5) wrote: "Although one may rub his body with oil, he may not apply cream because of the prohibition of Memare’aĥ, which is a tolada of Memaĥek (see below 18:6). Memaĥek refers to smoothing rough surfaces such as leather or wood, while Memare’aĥ involves evenly applying a substance to an object in order to make it smooth".
"Therefore, one may not apply any type of cream or ointment to the skin, because in doing so one smoothes the cream onto the skin. Some object that this should not be prohibited, since the cream is meant to be absorbed by the body rather than to remain on the surface of the skin. However, this is incorrect, since even when one wants the cream to be absorbed, he also wants some of it to remain on the skin’s surface to make it smooth. Hence the prohibition of Memare’aĥ applies. In contrast, if the cream is watery, such that if it is left on a surface it will spread out, there is no prohibition of Memare’aĥ, and one may apply it to the body."
In comment 3 he mentions: "If one would like all the cream to be absorbed into the body and none to remain on the skin, then there is no prohibition of Memare’aĥ (MA 316:24; MB ad loc. 49). Therefore, if one is sick enough that he may receive medical treatment on Shabbat, and he requires a cream, it may be spread on the skin and rubbed in until it is absorbed entirely by the body (Da’at Torah 328:26; R. Shlomo Zalman Auerbach cited in SSK ch. 33 n. 64). However, those who use cosmetic cream for pleasure or beauty do not want it to be entirely absorbed. Rather, they want some to stay on the surface of the skin, making it smooth and beautiful. Therefore, it is prohibited by Torah law to apply that cream."
By the way, the Peninei Halacha wrote at the end of the comment that it is prohibited by Torah law (deorayta). However see in the Shemirat Shabbat Ke'Hilchata (ibid) that it might actually be derabanan (a 'rabbinic law').
All the best
