The God of my mercy, i.e. the giver of all that mercy and comfort which I either have, or hope for. Heb. of his mercy. But here also there is (as appears by comparing this with Psa_59:17) a change of the person, as there was in the foregoing verse.
Shall prevent me, to wit, with the blessings of goodness, as it is more fully expressed, Psa_21:3. Thou shalt help me, and that seasonably, before it be too late, and sooner than I expect.
My desire in their disappointment and overthrow, as it follows; which was very desirable to David, no less for the public good, than for his own safety and happiness.