An Etymological Dictionary of the German Language/Pfahl
Pfahl, m,. from the equiv. MidHG. pfâl, OHG. pfâl, m., ‘pale, stake’; allied to the equiv. Du. paal, AS. pâl, E. pole, pale. The cognates were undoubtedly borrowed from Lat. pâlus (whence also Fr. pal) contemporaneously with the cognates of Pfosten, and probably also with the technical terms relating to building in stone (Ziegel, Schindel, Wall, Mauer, and Pforte); all these words have undergone permutation in HG.; see also the following word.