Psalms 41:3

God's kindness and truth have often been the support and comfort of the saints when they have had most experience of man's unkindness and treachery. David here found them so, upon a sick-bed; he found his enemies very barbarous, but his God very gracious. I. He here comforts himself in his communion with God under his sickness, by faith receiving and laying hold of God's promises to him (Psa 41:1-3) and lifting up his heart in prayer to God (Psa 41:4). II. He here represents the malice of his enemies against him, their malicious censures of him, their spiteful reflections upon him, and their insolent conduct towards him (Psa 41:5-9). III. He leaves his case with God, not doubting but that he would own and favour him (Psa 41:10-12), and so the psalm concludes with a doxology (Psa 41:13). Is any afflicted with sickness? let him sing the beginning of this psalm. Is any persecuted by enemies? let him sing the latter end of it; and we may any of us, in singing it, meditate upon both the calamities and comforts of good people in this world. To the chief musician. A psalm of David.

41:3 when they are sick: This illness might be physical or spiritual (see 6:2; Ps 38).