Charles Ellicott Commentary Psalms 41:8

"An evil disease, [say they], cleaveth fast unto him; And now that he lieth he shall rise up no more." — Psalms 41:8 (ASV)

An evil disease. —In the margin: thing of Belial. (For “Belial,” see Deuteronomy 13:13.) The expression may mean, as in the Septuagint and Vulgate, “a lawless speech”; the Chaldee, “a perverse word”; the Syriac, “a word of iniquity”; or “a physical evil,” as in the Authorised Version; or “a moral evil.”

The verse is difficult, not only because of this ambiguity in the expression but also because of the ambiguity of the verb. Depending on its derivation, the verb may mean “cleave” or “pour forth.” Modern scholars prefer the latter, understanding the image as taken from the process of casting metal: An incurable wound is poured out (welded) upon him. (Compare “molten,” 1 Kings 7:24, 30.)

This interpretation, however, does not suit the context nearly as well as the following reading:

“A wicked saying have they directed against me:
Let the sick man never rise again,”

which has the support of the Septuagint and Vulgate, though they render the last clause as a question: “Shall not the sleeper rise again?”