Is the sale of an estate excluding a specific area measure valid?
Chapter on Selling Assets and Fruits
Al-Mughni
Book of Sales
Primary text
The sale of an estate (day'ah) excluding a specific measure of land area, such as a jerib, is valid provided that both parties know the total area of the estate being sold. This follows the principle that a known portion can be excluded from a known whole.
Supporting text
If the total area of the estate is unknown to the contracting parties, the sale is deemed invalid because the excluded portion is indeterminate.