Adam Clarke on Ecclesiastes 10:8

Whoso breaketh a hedge, a serpent shall bite him - While spoiling his neighbor's property, he himself may come to greater mischief: while pulling out the sticks, he may be bit by a serpent, who has his nest there. Some have supposed that נחש nachash here means a thorn; perhaps from the similarity of its prick to the serpent's sting. He who forces his way through a hedge will be pricked by the thorns.