shabbat 9

thresholds in space and time.

and how broken scissors (or a loose belt) can impede the proper order to the afternoon

(finishing discussions about carrying in various domains, the talmud defines the domain of a threshold, the boundary space. the next mishna talks about activities one shouldn't start near the time of saying the afternoon prayer, lest they over-run and one misses Mincha. for english translation of this talmud page, see here)