...you shall not work with your firstborn bull... (Deuteronomy 15:19)
If an animal has been set aside to be used as a sacrifice, we may not use it to do any work (such as pulling a plow). The law is stated here regarding bechoros (first-born animals) and other consecrated animals are derived from it (see Talmud Bechoros 25a). This law also applies to shearing consecrated animals (as we will see in the next mitzvah) or using them in any other way. It likewise applies not only to animals intended for offerings but also to those donated for the financial upkeep of the Temple (albeit by rabbinic law). If someone misused Temple property by accident, he would have to pay the value of the benefit he received adding one-fifth, plus he would have to bring a guilt-offering. (As an aside, misappropriation of Temple property is called me’ilah.)
The reason for this mitzvah is to keep us far away from misuse of consecrated items. We must have reverence and awe for the Temple service. Taking a cow intended for the altar and hooking it to a wagon is a gross misuse of something that has been sanctified, as well as disrespectful towards to One for Whom it was sanctified.
This mitzvah applies in all times and places. It is discussed in the Talmud in tractate Makkos (21b-22a) and in Chulin (130a, 132a-b). It is codified in the Mishneh Torah in the first chapter of Hilchos Me’ilah. This mitzvah is #113 of the 365 negative mitzvos in the Rambam’s Sefer HaMitzvos; it is not listed in the Sefer HaMitzvos HaKatzar of the Chofetz Chaim.