Depart from me, all ye workers of iniquity - Referring, by the “workers of iniquity,” to his enemies, as if they now surrounded him, and calling on them “now” to leave him, since God had heard his prayer, and they could not be successful in their purposes. This is an indirect but most emphatic way of saying that God had heard his prayer; and the sentiment in this verse is strongly in contrast with the desponding state of feeling - the deep and dreadful sorrow - indicated in the previous verses. Light broke in suddenly upon him; his prayer had come up before God, and, in some way, he was assured that it would be answered. Already he sees his enemies scattered, and his own cause triumphant; and in this exulting feeling he addresses his foes, and commands them to leave him. This is, therefore, a remarkable and striking proof that prayer may be heard, even while we are speaking to God (compare Isaiah 65:24); that the assurance may be conveyed suddenly to the mind that God will hear and answer the prayer which is addressed to him; and also a beautiful illustration of the effect of this on a mind overwhelmed with trouble and sorrow, in giving it calmness and peace.
For the Lord hath heard - That is, my prayer has ascended before him, and I am certain that he regards it favorably, and will answer it. “In what way” he had this assurance he does not inform us. As he was an inspired man, we may suppose that the assurance was given to him directly by the Holy Spirit. “We” are not to expect the “same kind” of assurance that our prayers are heard; we are to look for no revelation to that effect; but there may be “as real” an intimation to the mind that our prayers are heard - as real “evidence” - as in this case. There may be a firm confidence of the mind that God is a hearer of prayer now coming to the soul with the freshness of a new conviction of that truth; and there may be, in trouble and sorrow, a sweet calmness and peace breathed through the soul - an assurance that all will be right and well, as if the prayer were heard, and such as there would be if we were assured by direct revelation that it is heard. The Spirit of God can produce this in our case as really as he did in the case of David.
The voice of my weeping - The voice of prayer that accompanied my weeping, or the voice of the weeping itself - the cry of anguish and distress which was in itself of the nature of prayer.