Psalms 94:18 - Coke's Commentary on the Holy Bible

When I said, My foot slippeth— The slipping or moving of the foot, is an expression which we often meet with, to signify any inevitable danger, as it does here; and it seems to be a metaphor taken from the sure consequence of such an accident, when two men are engaged at single combat; in which case, if one of them trips and falls, his adversary has him at his mercy.