Moab is my washpot — i.e., probably the footbath, a figure expressing great contempt, which receives illustration from the story told of Amasis (Herod. ii. 172) and the golden footpan, which he had broken to pieces and made into an image of one of the gods — from base use made divine — as allegorical of his own transformation from a private person to a king. Others explain, from analogy of Arabic proverbs, that the conqueror would as it were wash his face white, i.e., acquire renown in Moab.
Possibly the comparison of Moab to a bath was suggested by its proximity to the Dead Sea, which might be said to be at the foot of Israel.
Over Edom... — The most natural explanation of this figure is that Edom is disgraced to the character of the slave to whom the conqueror tosses his sandals (na’al is collective), that they may be cleaned. (Comp. Matthew 3:11). The symbolic action of Ruth 4:7 had a different meaning, the transfer of a right of ownership, and so cannot be employed in illustration.
Of the “shoe,” as a figure of what is vilest and most common, Dr. J. G. Wetzstein quotes many Arabic proverbs. A covering for the feet would naturally draw to it such associations. (Comp. the use of footstool repeatedly in the Psalms, and Shakespeare’s use of foot,
“What my foot my tutor!” — Tempest.)
But the custom which Israel brought from Egypt (Exodus 3:3), of dropping the sandals outside the door of a temple, and even of an ordinary house, must have served still more to fasten on that article of dress, ideas of vileness and profanation.
Philistia, triumph thou because of me... — This cannot be the meaning intended by the clause, since it is quite out of keeping with the context, and in Psalms 108 we have the very opposite, “over Philistia will I triumph.” We must therefore change this reading so as to get, over Philistia is my triumph, or render the text as it stands, from analogy with Isaiah 15:4 : Upon (i.e., because of) me, Philistia, raise a mournful wail.
The LXX. and Vulg. indicate this meaning while translating the proper name, “the foreigners have been subdued to me.”