638. Subordinate Labors

Shabbos 7:4

Similar to the examples in 7:2-3, whether one reaps grain or pulse, or if he harvests grapes, dates, olives or figs, they all represent the same primary category of labor because they all have the same goal: to remove produce from the place where it grows. The same idea applies with all the categories of labor.

Shabbos 7:5

A subordinate labor is an activity that resembles one of the categories of labor. For example, one who cuts a vegetable into small pieces for cooking is liable because this activity is similar to grinding. When one grinds, he takes a large thing and breaks it down into smaller pieces. One who performs an activity resembling this is performing a subordinate labor of the category of grinding. The same is true of one who pulverizes metal into powder as goldsmiths do; he is performing a subordinate labor of the category of grinding.