822. The Labor of Completion

Shabbos 23:1

If a person makes a hole that can be used as an entrance and as an exit, such as a hole in a chicken coop that lets light in and foul air out, he is liable for performing the labor of completion (literally “the final hammer blow”). The Sages therefore prohibited opening any hole, even one intended only as an entrance or only as an exit, out of concern that one might open a hole that would render him liable. This is why one may not make a new hole in a barrel, nor enlarge an existing hole. It is permitted, however, to re-open an existing hole as long as it is not below the level of the dregs. Since a hole that is sealed below the level of the dregs is intended to remain sealed, we may not re-open it on Shabbos.

Shabbos 23:2

One may make a hole in a barrel’s seal in order to pour wine through it so long as he opens it from the top of the seal and not from the side, which resembles making a utensil. One may break open a barrel in order to access the dried figs it contains so long as he does not intend to make a utensil. Similarly, one may cut the top off of a wine barrel for his guests by using a sword without concern because his intention is strictly to act generously.