Ibn Ezra (11th century): The "Ancient of Days" is Michael the Archangel

In his commentary on Dan 7:14, Ibn Ezra (born 1089) identified the "Ancient of Days" with the archangel Michael. One can find his commentary on this verse here.

 

The identification is made in line 4, where Michael, the great prince, is identified as the Ancient of Days (emphasis added):

 

מיכאל שר הגדול כאשר יפרש והוא עתיק יומין