Where does it state in the Torah that city walls can consist of wires, poles and ropes?

This seems to be a very convenient device to get round the halacha of not carrying on Shabbat, just like the use of Shabbat lifts, motorbikes, telephones, microphone and other modern-day conveniences.

Surely none of these are in the spirit of Shabbat?

A: Indeed you won't find anywhere written in the Torah that one can carry in an eruv.

But likewise you won't find anywhere in the Torah the prohibition of carrying on Shabbat.

The same sages who have taught us the tradition that one may not carry in a public domain on Shabbat, also teach us under which circumstances it is permitted.

The column that offers everything you always wanted to know about Judaism but were afraid to ask. Rabbi Ephraim Guttentag is minister of St. Annes Hebrew Congregation, St. Annes-on-Sea, Lancashire.

Read his blog at www.stannessynagogue.com

Email questions to the rabbi to mail@jewishtelegraph.com