The language and style of Beowulf is Old English, though. Old English was a West Germanic language, already closely related to the North Germanic Old Norse and mutually intelligible to a high degree.

But it doesn't make sense to say "such interjections were unlikely to be used by speakers of Nordic languages in order to begin a tale" without some sort of explanation for the focus on "Nordic" languages. Subsequent comments have made it clear that the commenter is under the mistaken impression that Old English was a Nordic language. It was not.