880. Measuring the Techum

Shabbos 28:10

Regarding those who live in huts, the Shabbos boundary is measured from the entrances to their homes. If there are three courtyards with two houses in each courtyard, they are counted as a single entity. We imagine a square around it and measure 2,000 cubits around it as we do with other cities.

Shabbos 28:11

The Shabbos boundary in only measured using a rope of 50 cubits, neither shorter nor longer. The rope is made of flax, which will not stretch longer. When those measuring reach a ditch up to 50 cubits wide, it should be measured with this rope provided that the ditch is fewer than 4,000 cubits deep.