BAIS HAVAAD ON THE PARSHA BESHALACH 5779 Practical Halachos of Techum Shabbos

Techum Shabbos dictates that one may not walk more than 2000 amos on Shabbos past his location (or his contiguous inhabited area) when Shabbos began. Traveling less than 12 Mil is derabanan. More than 12 Mil outside the techum is subject to machlokes: Some hold it constitutes an issur deoraisa based on the pasuk Others hold, that too, is only derabanan.