These days the Jews make a great difference between meat, fish, and milk dishes, both in cooking and eating. They derive this difference from the second book of Moses, in which it is written Ex. 23.19: You shall not boil a kid in its mother's milk. On this basis they conduct a lengthy and subtle discussion how to handle meat and milk the right way, and they have written many books about it. They have two different cooking-utensils, one for the meat, the other for milk dishes. They mark the milk vessels with three special signs; they cut three notches in the wood, because the aforementioned verse occurs three times in the Law of Moses. Sometimes they write or draw the word Chálaf, milk, on the one, and Básar, meat, on the other. [The German text has the words in Hebrew script, and in his transliteration; the f is due to the devoicing of final consonants in Yiddish/German]
Every Jew always carries two knives, one for meat, and one for cheese and fish. The latter is also marked with three notches. [People carried their cutlery with them.]
If these utensils get mixed up and one is taken for the other, then they may not eat what was cooked in them. They break the earthenware; they put wooden ones in water, and clean them out; iron pots are heated to a glow, and they have specific regulations in this regard.
They do not cook meat and milk next to each other on the range, neither do they place them with each other on the table, but they make a distinction between them. They use a special tablecloth for meat, and a special one for milk or cheese.
If they eat meat or meat-broth, they must not eat cheese or other milk products for a whole hour. Some who are very pious wait a full six hours. (However, chicken may be eaten together with almond-milk.) If someone cannot wait that long, he must clean the meat off his teeth, rinse his mouth and take away the taste of the meat by eating a piece of dry bread.
If meat fat falls into a milk dish the latter is forbidden. However, if the dish is sixty times as much as the fat, it may be eaten.
They do not boil an egg in a meat pot. As a rule, if they need eggs for cooking, they break them first onto a dish or plate, or drop them from one [part of the] eggshell into the other, to see that there are no spots of blood in it. For this reason also the Jews always open boiled eggs at the tip, because sometimes a small vein with blood is found. If they cut up a chicken which has eggs in its body, they do not use the eggs unless they are soaked and rinsed off in salt and water.
They do not place meat and fish together on one table, nor do they cook or eat them together. They write that one who does so is liable to be afflicted with leprosy. So they wash their hands and their mouth between eating meat and fish, or eat fruit, or a dry piece of bread.
The Jews consider it to be a great and noble wisdom to know how to make all the distinctions in these matters, and in serious cases they always have to ask the most learned Rabbis for advice.
New kitchen utensils like knives, tumblers etc. made of gold, silver, tin, copper, or lead must be put in water and washed thoroughly. If any of those things can stand fire they must be put in it and cleansed. They prove this from the fourth book of Moses Num. 31.23: Everything that can withstand fire should be passed through it, so that it may be clean. And it shall also be put through the purifying water. (About that see the 19th chapter in the same book.) Here the Talmud says that those containers and utensils should be dipped into the water or spring in which the Jewish women take their bath and submerge after their monthly uncleanness, because such a woman is called Niddah in Hebrew and the water to wash away uncleanness is also called Me niddah. ["Niddah water"] Here the Jews give us to understand that you can easily recognize the donkey by its ears. The previous saying does not speak of any vessel, but only the goods which they plundered from their enemies the Midianites who at that time were vile and depraved people. Moses therefore pointed out to them that they should have nothing to do with them or their goods, unless the goods were first sanctified. However, the Jews will not use any utensils obtained from Christians, even new utensils, unless they are first cleansed, and thus even today they indicate that we are not purer and holier than the peoples of long ago who were expelled from the land of Canaan. They explicitly call us in their writings Temëim, unclean and unholy heathens. But for all that outward glitter, the Jews are no purer in their hearts, as Christ often reproached them in the New Testament.