Deliver me not over unto the will of mine enemies; literally, the soul of mine enimies; i.e. their desire (see Psalms 35:25; Psalms 41:2), which was no doubt to capture him, and. bring him a prisoner to Jerusalem.
For false witnesses are risen up against me. The party which attached itself to Absalom accused David of cruelty to the house of Saul (2 Samuel 16:8), and probably of other crimes and misdemeanours. Absalom himself accused him of a failure in his kingly duties (2 Samuel 15:8).
And such as breathe out cruelty; or, violence. To "breathe out" violence, threats, slaughter, malice, etc; is a common metaphor in many languages.