Hilchot Shabbat - פרק י״ז (ב)

<p><strong>Perek י״ז (ב): The Fine Print of Lechi and Korah</strong><br>What exactly makes a crossbeam or side post valid? This section sets the measurements: how wide and strong a Korah must be, how tall and wide an alley opening can be, and what to do with a breach in the wall. It also covers alleys with several openings, where to place the Lechi, and why a Korah must sit on top of the alley rather than beside it.</p>