# They will spread their hands in the midst of it

"The people of Moab will push their hands through the dung"

# as a swimmer spreads his hands to swim

"as if they were swimming"

# will bring down their pride

Yahweh humiliating a proud person is spoken of as if pride were something high and Yahweh would cause it to be low. 

# in spite of the skill of their hands

"in spite of the great things they have built" or "in spite of the great things they have done"