Charles Ellicott Commentary Proverbs 18:17

"He that pleadeth his cause first [seemeth] just; But his neighbor cometh and searcheth him out." — Proverbs 18:17 (ASV)

He that is first in his own cause seemeth just. —A man who tells his own story can make a good case for himself out of it, but his neighbour (i.e., his adversary in the suit) cometh and searcheth him, sifts his statements, and shows them to be untenable.