An Etymological Dictionary of the German Language/Annotated/Staffel
Staffel, feminine, ‘rung; step, degree,’ from Middle High German staffel (stâffel, usually stapfel), masculine and feminine, ‘grade, degree,’ Old High German stā̆ffal (stapsal), masculine, staffala, feminine, ‘foundation, basis, step.’ A derivative of the Teutonic root stap, ‘to go’ (in Stapfe and Stufe); allied to the Low German cognates of Stapel.