WITH ALL [KINDS OF FOOD] MAY ‘ERUV AND SHITTUF BE EFFECTED, EXCEPT WATER AND SALT
This refers to the fact that certain kinds of Shabbat domains are defined, in part, by the placement of food within them. Any kind of food is acceptable, according to this Mishnah, except for water and salt.
But are those the only exceptions?
R. Johanan ruled: No inference may be drawn from general rulings, even where an exception was actually specified.
Rabbi Johanan’s ruling is to note that just because an exception is mentioned, one cannot assume that they are the only exceptions. It is not intended to be a limiting factor.
Several examples are given. Among the most famous:
All positive precepts [the observance of] which is dependent on the time [of the day or the year] are incumbent upon men only, and women are free, but those which are not dependent on the time [of the day or of the year] are incumbent upon both men and women. (Kid. 34a)
A general rule if ever there was one! Women are exempt, according to the Talmud, from time-bound positive commandments. But there are several exceptions not mentioned there, which the rabbis point out.
Behold [the precepts of] unleavened bread, (Ex. 12:18) rejoicing [on the festival] (Deut. 16:11, 14) and Assembly (Deut. 31:12) each of which is a positive precept [the observance of] which is dependent on a certain specified time and are nevertheless incumbent upon women!
Now, of course this patriarchal assumption of the exclusion of women (exemption becomes exclusion) is very problematic. But the point here is to recognize one simple fact:
There’s always an exception.