Menachos 12:2-3
Menachos 12:2
If a person obligates himself to bring a flour offering made in a frying pan but then he brought one made in a deep-fry pan, or vice versa, then what he brought is valid but does not fulfill his obligation. If he obligated himself to bring specific flour as an offering to be made in a frying pan and he ended up making it in a deep-fry pan, or vice versa, then the offering is invalid. If he obligated himself to bring two isaron of flour in one vessel but he brought it in two vessels, or vice versa, then what he brought is valid but does not fulfill his obligation. If he obligated himself to bring two specific isaron of flour in one vessel and he ended up bringing them in two, or vice versa, then the offering is invalid. If he obligated himself to bring two isaron of flour in one vessel but he brought them in two vessels and it was pointed out to him that he was supposed to use one vessel, then if he offers them in one vessel, they are valid, and if he offers them in two vessels, they are invalid. If he obligated himself to bring two isaron of flour in two vessels but he brought them in one vessel and it was pointed out to him that he was supposed to use two, then if he offers them in two vessels, they are valid, while if he offers them in one vessel, they are considered like two flour offerings that got mixed up.
Menachos 12:3
If a person obligates himself to bring a flour offering of barley (which is wrong), he must bring one of wheat (which is right). If he obligates himself to bring a flour offering of coarse flour, he must bring one of fine flour. If he obligates himself to bring a flour offering without oil and frankincense, he must bring it with oil and frankincense. If he obligates himself to bring a flour offering from half an isaron, he must bring it from a whole isaron. If he obligates himself to bring a flour offering from an isaron and a half, he must bring two isaron. Rabbi Shimon exempts those who make such obligations because they didn’t commit in the way that people commit (i.e., their statements conflict with the reality of flour offerings and are therefore not binding).