Jehovah is eternal and never changes (Malachi 3:6), therefore He is eternally the same. If being eternally the same is a unique attribute which can only apply to Jehovah yet Hebrews 13:8 affirms Jesus as eternally the same, it follows that Jesus is undeniably Jehovah according to this one verse of Scripture.

In order to disprove this conclusion, one must either prove Jehovah is not eternally the same, or Jesus is not eternally the same or prove that being eternally the same is not a unique attribute to Jehovah.

Biblically and exegetically, I believe, that is impossible.

If this verse proves Jesus is eternal (and Jehovah), yet is distinct from the Father, then Oneness doctrine is destroyed and the doctrine of the Trinity is established as biblical fact.