Where was Grendel's arm displayed?

Several critics have debated where Beowulf displays Grendel's arm—inside Heorot or outside above the main entrance. A Scandinavian scholar recounts a tradition that existed until modern times in rural Sweden of nailing the wings of a predatory bird above the entrance to a home or stable to ward off evil and argues that it is possible that Beowulf places Grendel's arm over the entrance to Heorot as both a trophy and a talisman to keep evil from returning to Heorot. If a talisman, however, it fails miserably when Grendel's mother arrives for her revenge.
https://www.owleyes.org/text/beowulf/read/xii