Gittin Chapter 5, Mishnah 1. This chapter continues to deal with matters connected to tikkun olam - enactments the Sages instituted for the good of society - and it opens with the order of collection for damages, debts and a woman's kesubah.
"Hanizakin shamin lahem b'idis":
'Nizakin' are the payments a person makes for having damaged his fellow's property. The Mishnah rules that we assess them from idis - that is, the payment is evaluated from the finest of his properties. In the laws of the Sages there are three levels of property:
Zibburis - the lowest quality property.
Beinonis - the average level.
Idis - the finest property.
The one who caused the damage owes a set sum, but the assumption is that a person wants to hold on to his highest quality land. Even though a parcel of superior land is smaller in area - since the value paid is identical either way - the payer would prefer to pay specifically from his less valuable property and keep the idis in his own hands. Regarding this the Sages said that even though he would rather pay from the zibburis, he must pay from the idis: the best of his properties.
The Torah's approach versus the enactment of the Sages:
At first glance one could ask: if this is an enactment made for the sake of tikkun olam, the Torah itself already dictates that payment be made from the finest, as it says, "mitav sadeihu" - the best of his field. The answer is that the Tanna of our Mishnah holds that the Torah's intent is that the payment be the best relative to what the damaged party owns, while for the sake of tikkun olam the Sages enacted that the one who caused the damage pay from the best of his own properties.
For example: if the beinonis of the one who caused the damage is equal in value to the idis of the damaged party, by Torah law it would be enough for him to pay from his own beinonis, since it is like the idis of the damaged party. The Sages, however, enacted that he must give the best of his own - the idis of the one who caused the damage.
"U'v'chov b'beinonis":
One who repays a loan that he owes pays from the beinonis. From the Torah we learn from a verse that the lender collects only from the zibburis, from the poorest of the borrower's properties; but the Sages enacted that repayment be made from the beinonis, from the average, so that people would be willing and interested in lending to others and would not worry that they would be repaid from the worst.
"U'kesubas ishah b'zibburis":
For payment of a kesubah, payment from the zibburis, from the lowest level, is sufficient. Here the Sages made no enactment, because there is no concern that women will refrain from marrying - the presumption is that a woman desires marriage even more than a man does. Therefore the law remains as the Torah established it from the outset: the kesubah is a debt, and its payment at the time of divorce is like the payment of any other debt, and so it remains at the Torah's level - zibburis.
Rabbi Meir disagrees and says: "Af kesubas ishah b'beinonis" - the very same enactment stated regarding repayment of a debt, that it be from the middle level, applies to a woman's kesubah as well.
In summary: In this Mishnah we learned three orders of collection: damages from idis, a debt from beinonis, and a woman's kesubah from zibburis. We examined the three levels of property, the distinction between Torah law - the best relative to the damaged party's properties, and collection of a debt from zibburis - and the enactments of the Sages for the sake of tikkun olam, that the one who caused the damage pay from the best of his own properties and that a creditor collect from beinonis so that the door not be closed before borrowers. We also saw why no such enactment was made regarding the kesubah, and the position of Rabbi Meir, who disagrees and holds that a woman's kesubah too is collected from beinonis.