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
isa 55:1THE CALL OF THE GENTILE WORLD TO FAITH THE RESULT OF GOD'S GRACE TO THE JEWS FIRST. (Isa 55:1-13)
every one--After the special privileges of Israel (Isa. 54:1-17) there follow, as the consequence, the universal invitation to the Gentiles (Luk 24:47; Rom 11:12, Rom 11:15).
Ho--calls the most earnest attention.
thirsteth--has a keen sense of need (Mat 5:6).
waters . . . wine and milk--a gradation. Not merely water, which is needed to maintain life at all, but wine and milk to strengthen, cheer, and nourish; the spiritual blessings of the Gospel are meant (Isa 25:6; Sol 5:1; Joh 7:37). "Waters," plural, to denote abundance (Isa 43:20; Isa 44:3).
no money--Yet, in Isa 55:2, it is said, "ye spend money." A seeming paradox. Ye are really spiritual bankrupts: but thinking yourselves to have money, namely, a devotion of your own making, ye lavish it on that "which is not bread," that is, on idols, whether literal or spiritual.
buy . . . without money--another paradox. We are bought, but not with a price paid by ourselves (Co1 6:20; Pe1 1:18-19). In a different sense we are to "buy" salvation, namely, by parting with everything which comes between us and Christ who has bought it for us and by making it our own (Mat 13:44, Mat 13:46; Luk 12:33; Rev 3:18).
isa 55:2not bread-- (Hab 2:13). "Bread of deceit" (Pro 20:17). Contrast this with the "bread of life" (Joh 6:32, Joh 6:35; also Luk 14:16-20).
satisfieth not-- (Ecc 1:8; Ecc 4:8).
hearken . . . and eat--When two imperatives are joined, the second expresses the consequence of obeying the command in the first (Gen 42:18). By hearkening ye shall eat. So in Isa 55:1, "buy and eat." By buying, and so making it your own, ye shall eat, that is, experimentally enjoy it (Joh 6:53). Compare the invitation (Pro 9:5-6; Mat 22:4).
fatness-- (Psa 36:8; Psa 63:5).
isa 55:3me . . . live--by coming to me ye shall live: for "I am the life" (Joh 14:6).
everlasting covenant-- (Jer 32:40; Sa2 23:5).
with you . . . David--God's covenant is with the antitypical David, Messiah (Eze 34:23), and so with us by our identification with Him.
sure--answering to "everlasting," irrevocable, unfailing, to be relied on (Psa 89:2-4, Psa 89:28-29, Psa 89:34-36; Jer 33:20-21; Sa2 7:15-16; Co2 1:18-20).
mercies of David--the mercies of grace (Isa 63:7; Joh 1:16) which I covenanted to give to David, and especially to Messiah, his antitype. Quoted in Act 13:34.
isa 55:4him--the mystical David (Eze 37:24-25; Jer 30:9; Hos 3:5). Given by God (Isa 49:6).
witness--He bore witness even unto death for God, to His law, claims, and plan of redeeming love (Joh 18:37; Rev 1:5). Revelation is a "testimony"; because it is propounded to be received on the authority of the Giver, and not merely because it can be proved by arguments.
commander--"preceptor" [HORSLEY]; "lawgiver" [BARNES].
to the people--rather, "peoples."
isa 55:5thou--Jehovah addresses Messiah.
call . . . run--God must call, before man can, or will, run (Sol 1:4; Joh 6:44). Not merely come, but run eagerly.
thou knowest not--now as thy people (so in Mat 7:23).
nation . . . nations--gradation; from Israel, one nation, the Gospel spread to many nations, and will do so more fully on Israel's conversion.
knew not thee-- (Isa 52:15; Eph 2:11-12).
because of . . . thy God . . . glorified thee-- (Isa 60:5, Isa 60:9; Zac 8:23); where similar language is directed to Israel, because of the identification of Israel with Messiah, who is the ideal Israel (Mat 2:15; compare with Hos 11:1; see Act 3:13).
isa 55:6The condition and limit in the obtaining of the spiritual benefits (Isa 55:1-3): (1) Seek the Lord. (2) Seek Him while He is to be found (Isa 65:1; Psa 32:6; Mat 25:1-13; Joh 7:34; Joh 8:21; Co2 6:2; Heb 2:3; Heb 3:13, Heb 3:15).
call--casting yourselves wholly on His mercy (Rom 10:13). Stronger than "seek"; so "near" is more positive than "while He may be found" (Rom 10:8-9).
near--propitious (Psa 34:18; Psa 145:18).
isa 55:7unrighteous--Hebrew, "man of iniquity"; true of all men. The "wicked" sins more openly in "his way"; the "unrighteous" refers to the more subtle workings of sin in the "thoughts." All are guilty in the latter respect, thought many fancy themselves safe, because not openly "wicked in ways" (Psa 94:11). The parallelism is that of gradation. The progress of the penitent is to be from negative reformation, "forsaking his way," and a farther step, "his thoughts," to positive repentance, "returning to the Lord" (the only true repentance, Zac 12:10), and making God his God, along with the other children of God (the crowning point; appropriation of God to ourselves: "to our God"). "Return" implies that man originally walked with God, but has apostatized. Isaiah saith, "our God," the God of the believing Israelites; those themselves redeemed desire others to come to their God (Psa 34:8; Rev 22:17).
abundantly pardon--Literally, "multiply to pardon," still more than "have mercy"; God's graciousness is felt more and more the longer one knows Him (Psa 130:7).
isa 55:8For--referring to Isa 55:7. You need not doubt His willingness "abundantly to pardon" (compare Isa 55:12); for, though "the wicked" man's "ways," and "the unrighteous man's thoughts," are so aggravated as to seem unpardonable, God's "thoughts" and "ways" in pardoning are not regulated by the proportion of the former, as man's would be towards his fellow man who offended him; compare the "for" (Psa 25:11; Rom 5:19).
isa 55:9(Psa 57:10; Psa 89:2; Psa 103:11). "For" is repeated from Isa 55:8. But MAURER, after the negation, translates, "but."
isa 55:10The hearts of men, once barren of spirituality, shall be made, by the outpouring of the Spirit under Messiah, to bear fruits of righteousness (Isa 5:6; Deu 32:2; Sa2 23:4; Psa 72:6).
snow--which covers plants from frost in winter; and, when melted in spring, waters the earth.
returneth not--void; as in Isa 55:11; it returns not in the same shape, or without "accomplishing" the desired end.
isa 55:11(Mat 24:35). Rain may to us seem lost when it falls on a desert, but it fulfils some purpose of God. So the gospel word falling on the hard heart; it sometimes works a change at last; and even if so, it leaves men without excuse. The full accomplishment of this verse, and Isa 55:12-13, is, however, to be at the Jews' final restoration and conversion of the world (Isa 11:9-12; Isa 60:1-5, Isa 60:21).
isa 55:12go out--from the various countries in which ye (the Jews) are scattered, to your own land (Eze 11:17).
led--by Messiah, your "Leader" (Isa 55:4; Isa 52:12; Mic 2:12-13).
mountains . . . trees, &c.--images justly used to express the seeming sympathy of nature with the joy of God's people. For, when sin is removed, the natural world shall be delivered from "vanity," and be renewed, so as to be in unison with the regenerated moral world (Isa 44:23; Psa 98:8; Rom 8:19-22).
isa 55:13thorn--emblem of the wicked (Sa2 23:6; Mic 7:4).
fir tree--the godly (Isa 60:13; Psa 92:12). Compare as to the change wrought, Rom 6:19.
brier--emblem of uncultivation (Isa 5:6).
myrtle--Hebrew, Hedes, from which comes Hedassah, the original name of Esther. Type of the Christian Church; for it is a lowly, though beautiful, fragrant, and evergreen shrub (Psa 92:13-14).
for a name . . . everlasting sign--a perpetual memorial to the glory of Jehovah (Jer 13:11; Jer 33:9).