Jamieson, Fausset & Brown

Arise, O Lord--God is figuratively represented as asleep to denote His apparent indifference (Psa 7:6). The use of "cheekbone" and "teeth" represents his enemies as fierce, like wild beasts ready to devour (Psa 27:2), and smiting their cheekbone (Kg1 22:24) denotes violence and insult. thou hast broken--God took his part, utterly depriving the enemy of power to injure.