"O LORD, rebuke me not in your anger,
  nor discipline me in your wrath.
 Be gracious to me, O LORD, for I am languishing;
  heal me, O LORD, for my bones are troubled.
 Psalm 6:1-2 

 O Lord, rebuke me not in thine anger. The Psalmist is very conscious that he deserves to be rebuked, and he feels, moreover, that the rebuke in some form or other must come upon him, if not for condemnation, yet for conviction and sanctification. "Corn is cleaned with wind, and the soul with chastenings." It were folly to pray against the golden hand which enriches us by its blows. He does not ask that the rebuke may be totally withheld, for he might thus lose a blessing in disguise; but, "Lord, rebuke me not in thine anger." If you remind me of my sin, it is good; but, oh, remind me not of it as one incensed against me, lest thy servant's heart should sink in despair. Thus saith Jeremiah, "O Lord, correct me, but with judgment; not in thine anger, lest thou bring me to nothing."

  I know that I must be chastened, and though I shrink from the rod yet do I feel that it will be for my benefit; but, oh, my God, chasten me not in thy hot displeasure, lest the rod become a sword, and lest in smiting, thou shouldest also kill.  So may we pray that the chastisements of our gracious God, if they may not be entirely removed, may at least be sweetened by the consciousness that they are "not in anger, but in his dear covenant love."

 Verse 2.    Have mercy upon me, O Lord; for I am weak.   Though I deserve destruction, yet let thy mercy pity my frailty.    This is the right way to plead with God if we would prevail.  Urge not your goodness or your greatness, but plead your sin and your littleness.  Cry, "I am weak," therefore, O Lord, give me strength and crush me not.    Send not forth the fury of thy tempest against so weak a vessel.    Temper the wind to the shorn lamb.   Be tender and pitiful to a poor withering flower, and break it not from its stem.   Surely this is the plea that a sick man would urge to move the pity of his fellow if he were striving with him,  "Deal gently with me, `for I am weak.'"    A sense of sin had so spoiled the Psalmist's pride, so taken away his vaunted strength, that he found himself weak to obey the law, weak through the sorrow that was in him, too weak, perhaps, to lay hold on the promise. "I am weak." The original may be read, "I am one who droops," or withered like a blighted plant.  Ah! beloved, we know what this means, for we, too, have seen our glory stained, and our beauty like a faded flower.

  by Charles Spurgeon