693. Walking vs. Stopping

Shabbos 13:8

If a person stands in either the public domain or a private domain and another person puts an item in his hand or on his back, and the first person then goes into the other type of domain with the item, he becomes liable when he stops in his place. Removing his body while carrying the item is classified as uprooting the item from the first domain and standing still with the item is classified as putting it down. Therefore, if he went out with the item but he didn’t stand still in the second domain, but rather he went back to the first domain still holding the item, he is not liable. This is so even if he goes in and out of his domain all day long until Shabbos ends because even though he uprooted the item, he did not put it down in the opposite domain. He isn’t even liable if he stands still to adjust his burden; in order to be liable, one must pause in order to rest.

Shabbos 13:9

Based on the reasons described in 13:8, if a person is carrying a burden on his shoulders and running, he is not liable until he stands still, even if he runs all day. But he must be running - if he walks slowly, it is comparable to removing the object and placing it down, which is prohibited. Therefore, a person who is carrying something on his shoulders when Shabbos begins should run with it until he gets home, at which point he should throw the item inside in an unusual manner.