Psalm 108:9 New English Translation

⁹Moab is my washbasin.^[a]
I will make Edom serve me.^[b]
I will shout in triumph over Philistia.”

Psalm 108:9 sn The metaphor of the washbasin, used to rinse one’s hands and feet, suggests that Moab, in contrast to Israel’s elevated position (vv. 7-8), would be reduced to the status of a servant.
Psalm 108:9 tn Heb “over Edom I will throw my sandal.” The point of the metaphor is not entirely clear. Some interpret this as idiomatic for “taking possession of.” Others translate עַל (ʿal) as “to” and understand this as referring to a master throwing his dirty sandal to a servant so that the latter might dust it off.

New English Translation (NET)