Here we'll talk about what happens when one of the inheritors works on the estate before it's divided up and improves its value. What happens to the profit after it's produced? Is it divided equally among the inheritors of the estate, or does it go only to the person, the inheritor, who worked?
The Mishnah says: If somebody passed away and left behind adult and minor sons, and the adult children worked the properties of the estate before they were divided, creating a profit and improving the land, it goes to the middle. In other words, the profits are shared equally by everybody, even though the adult sons—the ones who did all the work—hired the workers and made a plan for the estate and the property to generate a profit. We assume that they did it for everybody. We assume that they did it for their younger brothers as well, and therefore everybody splits it.
All this is said only when they don't spend their own money on the investment in the property. But if they do spend their own money on the investment in the property and do the work themselves, then they're entitled to keep all the improvements, all the profit, and they don't have to share with their younger brothers.
If they said, “See what property our father left us. Let's see the current value of the estate. Let's go work the land to improve its value, and we'll be ochel, we'll keep the profits,” then whatever improvement happens, they keep for themselves. Once they say that line, they have to say it to a Beit Din (rabbinical court). They're showing that their kavanah, their intention, is to do the work for themselves; their younger brothers, the minors, would not receive any part of the profits.
Same case with a woman who inherited her husband's estate along with the rest of her sisters, and they improved the property using the funds of the undivided estate. What's the story of this unusual type of scenario? Let's say there were two men. One of them's name was Reuven, and the other one was Shimon. Shimon died, and he left three daughters behind. So now Reuven goes and marries his niece. His niece. And then he dies, and he has no children either. So in such a scenario, Reuven's inheritors are going to be his three nieces. Among those three nieces, one happens to be his wife. So in an unusual case, a wife doesn't ever inherit a husband. She's not considered to be an inheritor. She has to be supported from the estate in some capacity, but she doesn't inherit him usually. So here, she happens to be his niece as well, so she inherits from her husband along with the rest of her sisters, and they improve the property. Whatever improvement happens to the land, whatever profits are created, are shared equally by everybody.
But if she says it before witnesses or before Beit Din, “Look what my husband left me. I'm going to work it now, and I'm going to improve the estate, and I'm going to keep the profits,” whatever she improves, she keeps for herself. We say that because the Beit Din allowed it, and the other heirs, the other inheritors, didn't say anything, they probably want the land to be producing. They don't want it to lie without work. They want it to actually be... So they're okay with this arrangement. She's doing it on her own. She's not taking it from the principal, so they'd be okay with her keeping whatever profits there are.