780. Working Animals on Shabbos
Shabbos 19:26
On Friday afternoon, a little before nightfall, a tailor should not go carrying a needle, nor a scribe with a pen, out of concern that he may forget and end up transporting it on Shabbos. One is required to check his clothes on Friday afternoon before nightfall out of concern that he may forget something in them and end up transporting it on Shabbos. One is permitted to go out wearing tefillin on Friday close to sunset. Since one is required to constantly touch his tefillin, it is impossible that he will forget that he’s wearing them. If a person absentmindedly goes out into a public domain while wearing tefillin, when he realizes it, he should cover his head until he reaches home or the study hall.
Shabbos 20:1
It is prohibited to transport a burden on an animal on Shabbos; Exodus 23:12 says, “your ox and your donkey shall rest.” This is just an example – it is not limited to oxen and donkeys. Rather, all domestic animals, wild animals and birds are included. Even though one is required to have his animals rest on Shabbos, he would not be liable if he causes them to work because it is a prohibition that is inferred from a positive commandment. Therefore, one who steers an animal that is carrying a burden on Shabbos is not liable.