Job 18:8

For he is cast into a net by his own feet. He walks of his own accord into a snare, not necessarily into one that he has himself set for others, as in Psalms 7:15; Psalms 9:15; Psalms 35:8; Psalms 57:6; and Proverbs 26:27; but either into one of his own setting, or into one laid for him by others (see Proverbs 26:10).

And he walketh upon a snare. A mere repetition of the idea expressed in the preceding hemistich.