Nedarim 12B

והא תרומת לחמי תודה ⁠— לאחר זריקת דמים היא.

Having made this inference, Ravina comments: But the teruma of the loaves of the thanks-offering is designated only after the sprinkling of the blood. Consequently, the individual must have made his vow after the sprinkling of the blood, when these loaves are permitted to priests. If the vow nevertheless takes effect, it must be because the individual is referring to the original forbidden status of the loaves before the sprinkling of the blood. This indicates that one has in mind the original status of the item rather than its current status.

אימא: ״כתרומת הלשכה״⁠ — אסור.

The Talmud refutes this: Say that when the Mishnah specifies that if one said the food should be like the teruma of Aaron it remains permitted it thereby indicates that if he said it should be like the collection of the Temple treasury chamber, which is also called a teruma and is always forbidden, the food becomes forbidden. However, one cannot infer from the Mishnah that if one declares the food to be like the teruma of the loaves of the thanks-offering the food becomes forbidden.

אבל תרומת לחמי תודה מאי ⁠— מותר? ליתני לחמי תודה, וכל שכן תרומתו! הא קא משמע לן תרומת לחמי תודה ⁠— תרומתו היא.

The Talmud asks: But according to this, if one said the food should be like the teruma of the loaves of the thanks-offering, what, does the food remain permitted? If so, let it teach in the Mishnah that if one said the food should be like the teruma of the loaves of the thanks-offering it remains permitted even though the thanks-offering is forbidden by means of a vow, and one would know on his own that if he says the food should be like the teruma of Aaron, all the more so the food remains permitted. The Talmud responds: It teaches us this: Teruma of the loaves of the thanks-offering is also referred to as his teruma and is therefore included in the Mishnah.