1) Meat must be salted (to extract the blood) within three days after the slaughtering. If it wasn't salted, it must be thoroughly rinsed with water within that three day limit, or else it becomes forbidden. 2) The Rabbis prohibited making preparations on Shabbat, for after Shabbat. Here, the meat being rinsed isn't going to be eaten on Shabbat, and therefore, it's clear that the rinsing is being done so as to keep it kosher for use after Shabbat. Although it's usually prohibited to ask a Gentile to perform a forbidden act on Shabbat for a Jew, in this case, since a financial loss is involved (i.e. the meat will become non-kosher), one may ask a Gentile to perform the task. The Mishna Berurah (321: 21) brings the opinion of the Eliyah Rabbah and Nodah BeYehuda that if it's impossible to find a Gentile to do it, a Jew may rinse the meat himself; in that case, if the meat is in a bowl, it's preferable for the Jew to rinse his hands over the meat in the bowl, so it's not as obvious that the intent is to rinse the meat.

1) One of the 39 Avot Melachot (prototype prohibited activity) is ''Scraping'' - ''Memachek'' - which refers to the act of scraping an animal hide to smooth its surface for use as parchment. Therefore, any act which involves smoothing - ''Memreach'' - out a moldable substance, such as wax, is prohibited as a derivative (Toldah) of ''Scraping''. For example, it's forbidden on Shabbat to use a solid bar of soap, or to spread cream on one's skin or on a cloth which will be applied to the body. Regarding a mild diaper rash on a baby, one may dab cream on the area and then cover it with the diaper, allowing the cream to spread by itself. Obviously, when dealing with severe diaper rash and other serious wounds, leniencies will apply with regard to spreading medication. 2) The general criterion is that if a substance cannot be poured like regular oil, and it doesn't flow by itself, but rather, one would have to spread it by hand, then it is forbidden to spread it. The majority of authorities rule that liquid soap is permitted on Shabbat, because of its relatively fluid consistency. However, there is an opinion that since liquid soap has some density, it is subject to the prohibition of ''Smoothing''. Those who follow this view, mix the soap with water (preferably before Shabbat) so that it's extremely fluid. 3) There is a dispute among the authorities as to whether the prohibition of ''Smoothing'' applies to food. Although we follow the lenient view which permits the spreading of food, one is considered praiseworthy if one refrains from smoothing out food for decorative purposes, like the icing on a cake. There is no need to be stringent when spreading food without concern for making the surface appear smooth.

אסור למרח רטיה וכן שעוה או זפת לכן אסור ליתן שעוה או שמן עב בנקב לסתמו או לדבקו על איזה דבר לסימן אבל אוכל מותר למרח כגון חמאה על הלחם וכדומה

1) One of the 39 Avot Melachot (prototype prohibited activity) is ''Cutting'' - ''Mechatech''- which involves intentionally breaking or cutting something to a specific size. This is different to the Av Melacha called ''Tearing'' - ''Koreah'' - which prohibits tearing or cutting any soft material (for a constructive purpose, but not with intent for a specific size), or separating two items that were sewed or glued together. 2) Anything which is edible for an animal, such as soft pieces of wood, falls under this category of ''food'', even though it had not been specifically set aside as animal fodder before Shabbat (Mishna Berurah 322:9). 3) Besides the prohibition of ''Cutting'', there is another prohibition involved here, which forbids turning anything into a useful object on Shabbat - ''Tikkun Keli''. Something defined as ''food'' (in this case, straw) cannot, according to the Gemara, be transformed into a ''vessel'' - ''Keli'' - and therefore isn't subject to the prohibition. 4) Since the purpose of the cutting is to increase the fragrance, and not to create a useful object (i.e. a toothpick), it's permissible, even though the wood is hard and thus not suitable as animal food. Pieces of wood which are neither fit for animal food, nor have a fragrance, are considered ''Muktza'' - ''set apart'' - which means they cannot be moved on Shabbat. 5) Making a toothpick out of hard wood (which is non-edible for animals) would be a violation of the prohibition of ''Cutting'' and, according to some, of the prohibition against creating a useful object - ''Tikkun Keli''. The Mishna Berurah (322:16) writes that many later authorities agree that when cutting hard wood to bring out its fragrance, one must use one's hands, not a knife, due to a concern that if one used a knife, one might decide to form a useful object, like a toothpick.