Does designating an animal for sacrifice make it obligatory, despite the desire for it to be voluntary, especially when it has been purchased in advance and marked?

There is a well-known difference of opinion among scholars regarding when an Udhiyah (sacrificial animal) becomes designated: The Hanafis believe it becomes designated upon purchase. The Shafi'is and Hanbalis believe it is only designated by utterance (i.e., by saying: "This is an Udhiyah"). The Malikis believe it is only designated upon slaughter. The majority of scholars hold that mere purchase does not make the Udhiyah obligatory. The Udhiyah is a confirmed Sunnah, and it becomes obligatory through a vow or through designation. The meaning of its obligation is that it is not permissible to sell it, and it must be sacrificed itself, and its guarantee is incumbent if it is ruined due to negligence.