You wrote:
Ran onto this comment in an article by Glenn Peoples:Cottrell seems to have thought of the middle voice according to the classical meaning—that the middle voice in some way affects the subject. However, Mounce affirms that this is never the reflexive idea. (Basics of Biblical Greek page 224). He wrote, "If the subject of a verb performs an action to itself, this requires the reflexive pronoun. Rather in the middle, the subject does the action of the verb to the direct object, and yet the action of the verb in some way affects the subject." Thus Mounce's word about the middle voice contradicts the idea that the subjects in Romans 9:22 "prepared themselves for destruction" as Cottrell affirms.
In Romans 9:22 there is no subject regarding the preparation for destruction. We might think God is implied, but why did Paul leave God out? Couldn't it be because everywhere in the scriptures the actions of the persons are what bring the destruction on? And then in verse 23 where God has prepared the vessels of mercy, God is clearly the subject.A similar thing is true of the middle voice, where a person is the object of a verb, and yet there is no other person who is clearly the subject.