What is the shape of the techum boundary around a city — square or circular — and how are the corners treated?
Synopsis
The techum boundary is configured as a square tablet: 2,000 cubits are measured along each side of the city, and then the corners are filled in as squares (2,000 x 2,000), giving a diagonal corner reach of 2,800 cubits. Measuring diagonally from the corner center is prohibited as it loses the extra 800 cubits.
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What type and length of rope must be used when measuring the Shabbos limit (techum)?
4 opinions
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At what height on the body must each person hold the measuring rope, and how tightly must it be stretched?
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Must the techum always be measured directly opposite the city, even when terrain obstacles make measurement difficult?
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How is a steep hill (one whose plumb line does not diverge 4 cubits at the base) treated during techum measurement?
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How is a moderately steep hill (rising 10 handbreadths in 5 cubits) measured for the techum?
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When a hill that rises 10 handbreadths in 4 cubits cannot be spanned in 50 cubits, may it be measured by estimation alone (omdan) or must the 4-cubit rope kidor method be used?
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How is a valley measured for the techum — does the rule differ depending on whether the plumb line diverges 4 cubits?
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