Soheil - Baruch She-Kivanta! This is a very important question. A similar question is asked by the Bach in his commentary on the Tur. I will try, bs'd, to explain this, starting from the original sources.

1) The Gemara Bava Kama 85b tells us that an example of the damage of "Shevet"; which is when someone is forced to "sit" at home and is unable to go to work and earn money; is where A locked B in a room and prevented B from working. A must pay B what he would have earned if he would not have been locked in the room.

2) On the basis of the above law, the Bach, in his commentary on the Tur on Choshen Mishpat 263:6, asks a question on Rabeinu Asher here 20a (chapter 2 beginning of section 6) who cites our Tosfos word for word:- "even if someone drove his friend out of his house and locked the door in front of him [and thereby prevented him from renting out the house] this is considered merely Grama and he is exempt from payment". The question of the Bach is:- what is the difference between locking B in the room, where A must pay the salary that B lost, and between A locking the house and making B lose the rent money, where the law is that A does not have to recompense the money that B lost?!

3) The Bach answers this riddle by making a distinction between whether the damage started immediately or only later on. When A locked B in, the loss commenced immediately because B is prevented from working straight away. In contrast, when A drove B outside, B only started losing the rent afterwards, when he obtains tenants who are now prevented from hiring the house.

4) This distinction between damage that starts immediately and damage which only starts later, is actually a distinction made by Rabeinu Asher himself, to explain the fine difference between grama and garmi. This second passage of Rabeinu Asher is found in the 9th chapter of Bava Kama, near the end of section 13. Rabeinu Asher writes that if the damage starts immediately this is considered as garmi and he must pay. Therefore if B posseses a document which states that C owes him money and A burnt this document, this is garmi and A must pay, because the damage happened immediately since B lost his money on the spot. In contrast grama does not start immediately. If A broke a fence in front of B's animal which then burst out and did damage, A is exempt because the damage did not start immediately, but only later on when B's animal damaged.

5) To summarize, Tosfos 20a DH Zeh Ein writes that if A drove B out of his house this is only grama, because B only started losing money later on when he lost the potential tenants. Garmi is different, because it means that the loss starts right away, for instance the moment that the deed of debt was burnt up, when B loses his money straight away.

Soheil, thank you for sending this very good question.

May we hear good news soon!

Pesach Kasher veSameach

Dovid Bloom

Follow-up reply:

1) Here is a different approach to this question from the Ketzot HaChoshen on Shulchan Aruch Choshen Mishpat 333:2. He makes a distinction between a person damaging a person and a person damaging property. The Ketzot Hachoshen starts with the assumption that if A locks up B's store; thereby preventing B from selling his merchandise; A is exempt from payment, because this is grama [this is of course similar to our Tosfos, where A drove B out of his house and locked it up, preventing B from renting out the house -DB]. Again, the question is:- what is the difference between this and between the Gemara Bava Kama 85b where A has to pay when he locked B in his house and stopped him going to work?!

2) Ketzot explains that there is a difference between locking a person in his house, and between locking a person out of his house.

We should firstly note that there are 2 kinds of "Shevet"; 2 kinds of damages which involve making a person sit at home and lose earning time. The first way would be where A injured B. A has to pay for the physical damage he did to B and he also must pay for the time that B loses from work. The second way is where A locked B in his room. No physical damage is involved, only lost time from work. This is called "Shevet She-Lo beMakom Nezek"; the only loss is "sitting" at home, with no other damage involved.

3) The next stage of the argument is to point out that there is something special about the Halacha of "Shevet":- it only applies to damage done to a person. If one damages property there is no such Halacha that one may pay for "sitting". This is why A locking B's store is different than locking B out of his house. When A locked B's store he damaged his property, but when A locked B in his room he afflicted damaged on B himself. It is not physical pain, but he has limited the physical mobility of B, being cooped up in the house all day.

4) Ketzot now continues and states that the Halacha is that one is indeed liable for garmi, even though one is exempt for grama. However Ketzot asserts that the combination of garmi and Shevet only applies when one damages a person. Therefore when A locked B in his house he has to pay for lost earnings because this is garmi in Shevet on a person, but when A locked B's store or house, this is damage afflicted on property and there is no such Halacha of "Shevet" inflicted on property.

5) Back to our Tosfos Bava Kama 20a. When A drove B out of his house this is considered as damage on the house, not damage on B, since B cannot now let tenants into his house and accrue the rent. The Halacha is that one is not liable for garmi when one caused property to lie idle, unavailable for renting.

6) The coronavirus has made millions worldwide stay at home without work, but we can also look on the bright side since many are taking the oppotunity now to learn Torah at home!

Pesach Kasher veSameach

Dovid Bloom