In parsha Beshalach (Shemos 16:29) it says that the Jewish people should not collect the mon on Shabbos. Some opinoins identify this is as the source for not carrying on Shabbos. This prohibition incudes not carrying in a public area. On Shabbos a person cannot carry in a public area. If a person has a low platform in a public area it is still part of the public area and you can’t carry there on Shabbos. However if the platform is over 10 tefach high it becomes a private area where you can carry. Shabbos 92a discusses that one could be misled by this rule to believe that if you carry something in the public domain, but hold it higher than 10 tefach, then it is no longer in the public domain, hence allowed to be carried on Shabbos. The Gemara then gives a proof showing why just carrying something above 10 tefach does not create a private area for that item.
We know that the law against carrying on Shabbos derives from the carrying of the aron in the wilderness. A proof can be made that the aron was “carried” even though its bottom was lifted over 10 tefach from the ground. Since this was still carrying then it is a proof that carrying an item over 10 tefach high does not create a private domain.
The aron was 10 tefach in height. (See a) The rings for the poles used to carry the aron were 1/3 of the way down the side. (See b) The shoulder height of the average Israelite was 18 tefach. (See c) Using this information show how high off the ground was the aron when it was being carried. (Solve for d)?
c – 2/3a = d
18 – 2/3 * 10 = 11.33