Albert Barnes Commentary Psalms 129:5

"Let them be put to shame and turned backward, All they that hate Zion." — Psalms 129:5 (ASV)

Let them all be confounded and turned back ... - This might be rendered in the indicative, “they are ashamed,” but the connection seems to require the rendering in our version. It is a prayer that God would now interpose as he had done in former times, and that he would cause all the haters of Zion to be put to shame as formerly.