See Isaiah 11:11, Jeremiah 44:1, 44:15, Ezekiel 29:14, 30:14. The Targum translates it as Nasyotai or Gasyotai, denoting Casiotis, the district surrounding Mount Casius, east of Pelusium in Egypt. The Targum on 1 Chronicles 1:12 reverses the definition of Pathrusim and Casluchim. In the Midrash it is rendered as Parvitoth (Bereshith Rabbah 37).