Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos) By the Chofetz Chaim

This book lists the Torah mitzvos that can be observed today

First Section – the Positive Commandments

70. It is a positive commandment to unload a burden from your friend’s donkey that is suffering from being overloaded

As it states in Shemos (Exodus) 23:5, “If you see the donkey of your enemy suffering from burdens on its back… help him, you shall surely help him.” This applies even when the load on its back is more than is usual. A person is required to unload the items for free and not for pay. An elderly person, who it is not honorable for him to do this, is exempt from this commandment. If a person unloaded and then reloaded the animal, and again the items fell, the person is still required to help unload and load, even if it happens 100 times, as it states “you shall help him, you shall surely help him.” The helper is required to walk a parsa (approximately 3 miles) unless the owner tells him that he is not needed [this is to make sure the items do not fall again.]