Tractate Temurah - Chapter 5 - Mishnah 6 תמורה פרק ה׳ משנה ו׳

[If one says:] “Behold this animal shall be instead of a hatat,” [or] “instead of an olah,” he has said nothing. [But if he says:] “Instead of this hatat” [or] “Instead of this olah,” [or] “Instead of the hatat or the olah which I have in the house,” and he had it in the house, his words stand. If he says concerning an unclean animal or a blemished animal: “Behold these shall be an olah,” he has said nothing. [But if he says:] “Behold they shall be for an olah,” they are sold and he brings with their money an olah.