John Trapp on Psalms 21:12

Verſ. 12. Therefore ſhalt thou make them turn their back] Who faced the very Heavens, and ran, as it were, full butt againſt thee; ſuch was their impudence and inſolence. But thy wrath ſhall ſo meet them in the teeth, whereſoever they turn, that they ſhall bee forced to give over their chaſe and purſute of thy people. Thou ſhalt make them turn their back, Heb. their ſhoulder; whence ſome ſenſe the words thus, Thou ſhalt bind them back to back, and caſt them into the Sea of perdition. Some read the words thus,Pones eos ut meram. Kimchi Thou ſhalt ſet them as a Butt or Mark to ſhoot at; and this agreeth beſt with that which followeth.

Againſt the face of them] Which is elegantly campared to the white; as their bodies to the whole mark or Butt.