The Purest Definition of a Macguffin

I think what you say The movie can be this because we're gonna pop a Macguffin in here and it doesn't matter. I'll use like the lost Ark of the Covenant Technically, I'm not sure that a purest is a muffin a George Lucas word to it's a Hitchcock word right? But I think a purest would be like if I you same thing you know Lucas but the advice said if I if I a purest might slap me down and say no the Ark of the covenant is a MacGuffin Because we know it does something we know what it is. They have no idea why it's important or what they want to do with it