All types of korbanot (offerings) that were sanctified at the time when bamot (high places) were forbidden and were then offered up on a bamah at a time period where bamot were forbidden. So it was sanctified when it was forbidden, and it was also offered up on the bamah when it was forbidden to do so. He violated both a positive command to bring korbanot only inside the sanctuary of Hashem and, at the same time, a lo ta'aseh (prohibition), which does not allow him to bring any korbanot outside of the chatzer, the courtyard of the Bet HaMikdash (sanctuary).
We learn this first from Sefer Vayikra, where the pasuk (verse) says, “You have to bring these korbanot to the entrance of the Ohel Moed (Tent of Meeting).” That tells us that a person has to bring korbanot there. He also violated a lo ta'aseh, as the pasuk tells us, “Be very careful not to offer up an olah offering”—that really means all types of korbanot—“in any place that you want.” This tells us not only that you have to bring them to the Bet HaMikdash or the Mishkan (Tabernacle), but also that you are not allowed to bring them elsewhere. A person would also be liable for karet (excision) in this type of situation, because he brought a korban on a bamah outside of the Bet HaMikdash or the Mishkan.
The next case: He sanctified the korban at a time when bamot were permitted, but when he went to offer it up on the bamah, bamot were already forbidden. Let’s say he consecrated it—he sanctified it—at the time when the Mishkan was in Gilgal, when bamot were permitted, and then offered it up on a bamah later, when the Mishkan was built or moved to Shiloh, where bamot became forbidden. So what do we say in that case? He also violated the positive commandment and the lo ta'aseh, the prohibition. But when he went to offer it up on the bamah, he did not violate anything that would make him liable for karet for offering it outside. A person is liable for karet when bringing a korban outside only if he would also have been liable at the time he sanctified it. If he would have been liable at that time for doing something wrong, that is when we say there is karet. But in this type of situation, when the korban was sanctified at a time when bamot were allowed, were permitted, there is no karet for bringing the korban out later, after bamot became forbidden.
Now the opposite case: He sanctified the korban at a time when bamot were forbidden, but then offered it up on the Mizbeach (altar) or on a bamah at a time when bamot were permitted. He violated an aseh, a positive commandment. We have a positive commandment: the moment a person sanctifies something, he has to bring it to the Mishkan. So this person is going to be sort of timed out by delaying the korban for a certain amount of time and not bringing it right away. He violated the aseh because eventually the situation became one where you were allowed to bring it on a bamah, so therefore it was okay. He did not do anything wrong there, but since it was sanctified at a time when bamot were forbidden, he should have taken it immediately to the Mishkan in order to offer it there. So he has violated only an aseh, a positive commandment, but he did not violate the lav, and that’s what the Mishnah says, but he did not violate the prohibition, and obviously he did not violate anything that would make him liable for karet.