Charles Ellicott Commentary Daniel 4:33

"The same hour was the thing fulfilled upon Nebuchadnezzar: and he was driven from men, and did eat grass as oxen, and his body was wet with the dew of heaven, till his hair was grown like eagles` [feathers], and his nails like birds` [claws]." — Daniel 4:33 (ASV)

The thing fulfilled. Nebuchadnezzar's illness has frequently been a subject of discussion, and it is now generally agreed that it was a form of mania known as lycanthropy. Its distinctive features, mentioned in this verse, are partially connected with the life his delusion forced him to lead. It appears, however, from the account in Daniel, that he retained his consciousness, as he lifted up his eyes to heaven (Daniel 4:34) before his understanding returned to him. Of this sickness nothing is recorded by Berosus, unless the vague statement “Nebuchadnezzar fell sick and died after a reign of forty-three years” is pressed. It is remarkable to observe that an interval is mentioned in his inscription during which he carried out no great public works.