Halakhah for Shabbat 22:7

Memarei’ach refers to “smoothing soft, pliable substances that may be pressed or molded to a shape” (Rav Dovid Ribiat, The 39 Melochos, 3:913). A prime example of this is the Mishnah (Shabbat 22:3) that forbids spreading wax to seal a hole in a barrel. The Gemara (Shabbat 146b) records a dispute between Rav and Shmuel whether this prohibition applies also to spreading oil to seal such a hole. Rav asserts that it is a rabbinic prohibition⁵Memarei’ach on a biblical level applies only to pliable solids. Oil does not fall into this category and as such is prohibited only on a rabbinic level. to spread oil lest one come to spread wax, whereas Shmuel permits this activity, as he does not see the necessity for creating such a gezeirah (rabbinic enactment). The Halachah follows Rav (Rambam Hilchot Shabbat 23:11 and Shulchan Aruch O.C. 314:11), as is the usual protocol in the context of ritual matters (issurei). Rav Ribiat (The 39 Melochos 3:919) writes that rouge creams, eye-shadow creams, petroleum jelly, and hand creams such as Nivea and Desitin are included in this rabbinic prohibition.