Arise, O Lord! why sleepest thou? Here the saints desire that God, having pity upon them, would at length send them help and deliverance. Although God allows the saints to plead with him in this babbling manner, when in their prayers they desire him to rise up or awake; yet it is necessary that they should be fully persuaded that he keeps watch for their safety and defense. We must guard against the notion of Epicurus, who framed to himself a god who, having his abode in heaven, delighted only in idleness and pleasure. But as the insensibility of our nature is so great, that we do not at once comprehend the care which God has of us, the godly here request that he would be pleased to give some evidence that he was neither forgetful of them nor slow to help them. We must, indeed, firmly believe that God ceases not to regard us, although he appears not to do so; yet as such an assurance is of faith, and not of the flesh, that is to say, is not natural to us, the faithful familiarly give utterance before God to this contrary sentiment, which they conceive from the state of things as it is presented to their view; and in doing so, they discharge from their breasts those morbid affections which belong to the corruption of our nature, in consequence of which faith then shines forth in its pure and native character. If it is objected, that prayer, than which nothing is more holy, is defiled, when some froward imagination of the flesh is mingled with it, I confess that this is true; but in using this freedom, which the Lord vouchsafes to us, let us consider that, in his goodness and mercy, by which he sustains us, he wipes away this fault, that our prayers may not be defiled by it.

Awake, why sleepest thou? - This is a solemn and earnest appeal to God to interpose in their behalf, as if he were "asleep," or were regardless of their sufferings. Compare Psalm 3:7, note; Psalm 7:6, note; Psalm 35:23, note.
Arise, cast us not off for ever - Do not forsake us always. Compare Psalm 44:9. He had seemed to have cast them off; to have forgotten them; to have forsaken them utterly, and the psalmist, in the name of the people, calls on him not entirely to abandon them.

A wake, why steepest thou, O Lord? - That is, Why dost thou appear as one asleep, who is regardless of the safety of his friends. This is a freedom of speech which can only be allowed to inspired men; and in their mouths it is always to be figuratively understood.

Awake, why sleepest thou, O Lord?.... Not that sleep properly falls upon God: the Keeper of Israel neither slumbers nor sleeps; his eyes are always upon his people; he never withdraws them from them, and he watches over them night and day: but sometimes he seems and is thought to be asleep; as when wicked men flourish and triumph over the righteous, and go on in sin with impunity; when their judgment seems to linger, and their damnation to slumber, though it does not; and when the saints are under sore afflictions, and the Lord seems to disregard them, and does not appear for their deliverance; and when things are as when the disciples were in a storm, and Christ was asleep, to whom they said, "carest thou not that we perish?" and the Lord may be said to awake, and it is what is here prayed for, when he stirs up himself and takes vengeance on his enemies, as he will before long on antichrist and his followers; and when he takes in hand the cause and judgment of his people, and pleads it thoroughly, and delivers them out of the hands of all their oppressors, and gives them the dominion and kingdom under the whole heaven; see Isaiah 2:9;
arise; to revenge the blood of his people, and to have mercy on his Zion;
cast us not off for ever; as he might seem to do, by suffering their enemies to triumph over them; but in reality he does not; much less with loathing and abhorrence, as the word (r) used signifies, since his church is his Hephzibah, in whom he delights, Isaiah 62:4; and still less for ever, since his love to them is from everlasting to everlasting, and they shall be for ever with him; See Gill on Psalm 43:2.
(r) "ne abjicias cum fastidio", Gejerus.

This style of addressing God, as indifferent, is frequent (Psalm 3:7; Psalm 9:19; Psalm 13:1, &c.). However low their condition, God is appealed to, on the ground, and for the honor, of His mercy.