667. Other Forms of Completion

Shabbos 10:17

Piercing a blister on Shabbos renders one liable for performing a subordinate labor of completion if one’s intention is to widen the opening of the wound as this is an activity performed by doctors. If a person pierced it to remove the fluid, it is permitted.

Shabbos 10:18

Filing a stone even the smallest amount renders one liable for completion. Putting a stone into a building’s foundation and adjusting it into its proper place renders one liable for completion. Manually removing threads, straw or splinters of wood from a garment renders one liable for completion if their presence was bothering the person in question. If one removes them automatically, without specific intention, he is not liable. Shaking out a new black garment to make it look nicer and to remove any remaining bits of white wool as tailors do renders one liable, though if he is not bothered by the white bits, it is permitted.