אב ותולדות
How was טוחן done in the משכן?
Crush herbs or
grind flour
How is one חייב for טוחן by cutting vegetables?
Dicing into very small pieces.
What does אין טוחן אלא בגידולי קרקע mean?
That טוחן only applies to things that grow from the ground
What is the exemption of מיד?
It is מותר to grind for immediate use.
What is the reason why חז"ל prohibited medicinal interventions on שבת?
Because they were concerned that you might come to grind up medicine.
What is the שיעור to be חייב for טוחן?
גרוגרת
How small is considered small to be חייב for טוחן?
If you dice it דק דק - very small - is for sure חייב but since we don't know the exact size even dicing into larger pieces should only be done immediately prior to the meal.
What does אין טוחן אחר טוחן mean? Give an example!
After someyhing was ground there is no איסור to grind it again - like crumbling crackers.
In what way is the היתר of מיד by טוחן different than the היתר of מיד by בורר?
By בורר we do not allow an instrument that aids in the process but by טוחן one may use a knife.
What three exemptions os the prohibition of רפואה do we learn from סעיף לז?
מאכל בריאים
בריא
נופל למשכב
What is the underlying principle/premise of טוחן?
Breaking down something to small components.
What is the Halachically preferred way to cut vegetables for Israeli salad on Shabbos?
Dice into larger pieces than normal and only immediately prior to the meal.
Where does the concept of אין טוחן אחר טוחן apply to something that was never ground?
If something was cooked so that it is so soft it is already considered ground - like compote.
What is the exemption of שנוי? What is an example of a an acceptable שנוי by טוחן?
If you utilize a double change then it is מותר.
An example is crushing with the handle of a knife and on a plate.
Which type of non-medicinal progressive therapies are permitted on שבת and why? Give an example.
Things that are not usually addressed by medicine like hot compress stomach pain. The reason is that since medicine is not usually used to treat this ailment - this therapy was not prohibited by חז"ל to treat because there is no concern one might crush to make medicine.
Give an example of a תולדה of טוחן by wood.
Wood into woodchips.
Wood into sawdust.
Why is mashing bananas, according to Rav Moshe, not a problem of טוחן?
Because it never becomes separate particles - it remains one mass.
What are two exceptions to איו טוחן אלא בגידולי קרקע?
In an עובדא דחול way - Using a grinding כלי like a cheese grater
And אשויי אוכלא - grinding meat to make it edible for animals
What are two exceptions to the exemption of מיד?
Non-Food items
What is the basis to allow preventative medicine on שבת? Give two examples of preventative medicine.
Just like a protective bandage is permitted, because since it is preventative and not addressing a current stressful ailment there is no concern that one might impulsively grind medicine.
Lactaid before milk
Zyrtek before allergies start
Give an example of טוחן by earth.
Crumbling a hard clump of earth.
Why is slicing reeds into thin slices חייב but slicing vegetables into thin slices is not חייב?
The thin reeds are in their usable state, the thin vegetables still need to be chewed (and ground further).
Are animal products (cheese, eggs) considered גידולי קרקע?
Since it is a מחלוקת in general if animals are considered גידולי קרקע and here there are opinions that טוחן does not apply to edible foods we can be lenient.
What is the אגלי טל's question on the היתר of שנוי?
Why is a שנוי permitted by טוחן but for all other מלאכות it is still אסור מדרבנן?
What is the הלכה regarding exercising on שבת?
Since exercise is a progressive therapy, if it is not the actions of בריאים (like walking) it is אסור to do if one intends it to be exercise. Some prohibit even walking for exercise. If one is running for enjoyment then it is מותר.