Claudius Ptolemy

Greco-Egyptian astronomer and geographer. Author of an astronomical canon used for chronological calculations in the sacred chronology.

Commentary on the Pentateuch of Moses

• Sacred Chronology — The canon of Ptolemy used for chronological calculations

  "according to the canon of Ptolemy"

Chapter I (The Six Days of Creation)

• Verse 16: And God Made Two Great Lights — Cited alongside Alfraganus for dividing stars into six classes of magnitude

  "from the opinion of Ptolemy and Alfraganus"