Verse 24. My knees are weak through fasting; either religious fasting, to which he resorted in the dire extremity of his grief, or else through loss of appetite occasioned by distress of mind. Who can eat when every morsel is soured by envy? This is the advantage of the slanderer, that he feels nothing himself, while his sensitive victim can scarcely eat a morsel of bread because of his sensitiveness. However, the good God knoweth all this, and will succour his afflicted. The Lord who bids us confirm the feeble knees will assuredly do it himself. "And my flesh faileth of fatness." He was wasted to a skeleton, and as his body was emaciated, so was his soul bereft of comfort: he was pining away, and all the while his enemies saw it and laughed at his distress. How pathetically he states his case; this is one of the truest forms of prayer, the setting forth of our sorrow before the Lord. Weak knees are strong with God, and failing flesh has great power in pleading.