Matthew Poole and continuators on Psalms 41:4

4. I said LORD, be merciful unto me; heal my soul , for I have sinned against thee .

(i. e.) Either, 1. My self, to wit, my Body. So it is a double Synecdoche. And the soul is so taken. Psal. 16. 10. Or, 2. My Soul properly so called; which is said to be healed, when it is pardoned and purged, as 2 Chron. 30. 20. Isa. 53. 5. Comp. with 1 Pet. 2. 24. Mat. 13. 15. Comp. with Mark 4. 12. Iam. 5. 16. So he strikes at the Root of his Misery, and prays for the Removal of the sin of his Soul, as the Cause of the Disease of his Body.

This may be added Either, 1. As a Reason or Motive to God, grant this Request, for I have sinned, and therefore thy Grace in healing me, will be more glorious and admirable; Or, for I acknowledge that I have sinned: for the Act is oft put for the Declaration of it, as Exod. 33. 13. Psal. 51. 5. Or, 2. As a Reason moving him thus to pray, I said, Lord be merciful unto me, heal my Soul; and great Reason I had to say so, for I have sinned against thee.