Adam Clarke on Isaiah 25:11

As he that swimmeth spreadeth forth his hands to swim "As he that sinketh stretcheth out his hands to swim" - There is great obscurity in this place: some understand God as the agent; others, Moab. I have chosen the latter sense, as I cannot conceive that the stretching out of the hands of a swimmer in swimming can be any illustration of the action of God stretching out his hands over Moab to destroy it. I take השחה hashshocheh, altering the point on the ש sin. on the authority of the Septuagint, to be the participle of שחה shachah, the same with שוח shuach, and שחח shachach, to bow down, to be depressed; and that the prophet designed a paronomasia here, a figure which he frequently uses between the similar words שהח shachah, and שחות shechoth. As תחתיו tachtaiv, in his place, or on the spot, as we say in the preceding verse, gives us an idea of the sudden and complete destruction of Moab; so בקרבו bekirbo, in the midst of him, means that this destruction shall be open, and exposed to the view of all: the neighboring nations shall plainly see him struggling against it, as a man in the midst of the deep waters exerts all his efforts by swimming, to save himself from drowning. - L.