- If you were not yet mekabayl Shabbos, there are certain shvusim (which are not close to being a melacha) that are permitted during twilight erev Shabbos for the purpose of a mitzvah. (ShA – MB 1,2)
- For example, you are allowed to climb a tree or to swim in order to reach a lulav or shofar. A more common example is to instruct a non-Jew to turn on lights for Shabbos.. Make sure the non-Jew does not light them after bayn hashmashos. (ShA – MB 7)