A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
psa 49:1This Psalm instructs and consoles. It teaches that earthly advantages are not reliable for permanent happiness, and that, however prosperous worldly men may be for a time, their ultimate destiny is ruin, while the pious are safe in God's care. (Psa. 49:1-20)
All are called to hear what interests all.
world--literally, "duration of life," the present time.
psa 49:4incline--to hear attentively (Psa 17:6; Psa 31:2).
parable--In Hebrew and Greek "parable" and "proverb" are translations of the same word. It denotes a comparison, or form of speech, which under one image includes many, and is expressive of a general truth capable of various illustrations. Hence it may be used for the illustration itself. For the former sense, "proverb" (that is, one word for several) is the usual English term, and for the latter, in which comparison is prominent, "parable" (that is, one thing laid by another). The distinction is not always observed, since here, and in Psa 78:2; "proverb" would better express the style of the composition (compare also Pro 26:7, Pro 26:9; Hab 2:6; Joh 16:25, Joh 16:29). Such forms of speech are often very figurative and also obscure (compare Mat 13:12-15). Hence the use of the parallel word--
dark saying--or, "riddle" (compare Eze 17:2).
open--is to explain.
upon the harp--the accompaniment for a lyric.
psa 49:5iniquity--or, "calamity" (Psa 40:12).
of my heels--literally "my supplanters" (Gen 27:36), or oppressors: "I am surrounded by the evils they inflict."
psa 49:6They are vainglorious.
psa 49:7yet unable to save themselves or others.
psa 49:8it ceaseth for ever--that is, the ransom fails, the price is too precious, costly.
psa 49:9corruption--literally, "pit," or, "grave," thus showing that "soul" is used for "life" [Psa 49:8].
psa 49:10For he seeth--that is, corruption; then follows the illustration.
wise . . . fool-- (Psa 14:1; Pro 1:32; Pro 10:1).
likewise--alike altogether-- (Psa 4:8) --die--all meet the same fate.
psa 49:11Still infatuated and flattered with hopes of perpetuity, they call their lands, or "celebrate their names on account of (their) lands."
psa 49:12Contrasted with this vanity is their frailty. However honored, man
abideth not--literally, "lodgeth not," remains not till morning, but suddenly perishes as (wild) beasts, whose lives are taken without warning.
psa 49:13Though their way is folly, others follow the same course of life.
psa 49:14Like sheep--(compare Psa 49:12) unwittingly, they
are laid--or, "put," &c.
death shall feed on--or, better, "shall rule"
them--as a shepherd (compare "feed," Psa 28:9, Margin).
have dominion over--or, "subdue"
them in the morning--suddenly, or in their turn.
their beauty--literally, "form" or shape.
shall consume--literally, "is for the consumption," that is, of the grave.
from their dwelling--literally, "from their home (they go) to it," that is, the grave.
psa 49:15The pious, delivered from "the power of the grave."
power--literally, "the hand," of death, are taken under God's care.
psa 49:16applies this instruction. Be not anxious (Psa 37:1, &c.), since death cuts off the prosperous wicked whom you dread.
psa 49:18Though . . . lived, &c.--literally, "For in his life he blessed his soul," or, "himself" (Luk 12:19, Luk 16:25); yet (Psa 49:19); he has had his portion.
men will praise . . . thyself--Flatterers enhance the rich fool's self-complacency; the form of address to him strengthens the emphasis of the sentiment.
psa 49:20(Compare Psa 49:12). The folly is more distinctly expressed by "understandeth not," substituted for "abideth not."