A person rents a house from his friend on the 14th of Nisan. He does not know whether the house has been checked. If the landlord is in the city, he asks him, “Did you check it or not?” Right, on the 14th by day, or in the middle of the night of the 14th, meaning you gave the landlord enough time to make a Bedika (check). If the landlord is in town—or let’s say his family members are in town—you could ask them, meaning you could trust them.
Even against the Chazakah (status quo)—meaning, even though maybe you might assume that it wasn’t checked—you could trust a woman or the children to say that it was checked. Even though the normal way for kosher people is to check, to make Bedikat Chametz (check) on the 14th at night. And you assume that every Jew is doing the right thing. And you have to assume that when he checked, you still have to ask.
The Gemara is bothered: What do you have to ask him for? Don’t you assume that a Jew did his responsibility? Since it’s already the 14th, why do you even have to ask a question? Why can’t you just assume that he checked? He says, “No, there is no Chazakah, because here he’s already trying to take it out of its status. The status quo was already that there is Chametz (leavened food) in the house. And in Chazakah, you want to take it out of its status and just say, ‘Oh, well, you have to assume that it was checked.’ You assume—you can’t assume; you’ve got to ask. If you’re able to ask questions, you have to ask.”
Now, why would you have to make bitul (nullification)? Whose Chametz is going to be in that house? The landlord’s. It’s not your Chametz either. Which means, usually, when a guy rents a house to somebody, whatever he leaves in the house, he becomes ownerless. And therefore, it’s like gifting it to the tenant, and therefore, that Chametz becomes the tenant. So the tenant is going to have to make bitul on that Chametz.