Völuspá Edda-poem, is a compilation of vísur (verses) without any consistency of known rules of poetry, and, obviously there are some later-time Christian additions here too.
Helgi Hálfdánarson discovered 3 ancient poems as the main pillars of Völuspá, according to their bragarháttur (rules of metric in poetry in Iceland).
Helgi wrote the book “Maddaman með kýrhausin” (The Madame With a Cow´s Head) in 1962, reprint 2002 (if I remember correctly).
Perhaps these 3 poems Helgi discovered in Völuspá were saved by mixing them together and adding some Christian terms to the mixture, and some other meant-to-be interesting addition? Helgi jokes: Baptized to Christianity: „prímkristnun“.
Helgi names his 3 discovered poems Ásaspá, Mímisspá, and Járnviðja. And he published his Maddaman-book – to the great annoyance and jealousy of the scholars who did not see this obvious thing themselves, and in their wrath of envy entirely dismissed this great book as if it had never been written.
Same Völuspá Edda-poem on Youtube