The Pulpit Commentary
AN EXHORTATION TO SPIRITUALITY AND REPENTANCE. The prophet passes from the ideal to the actual, from the glorious future to the unsatisfactory present. The people are not ripe for the blessings of the Messianic kingdom—they do not sufficiently value them. Hence a tender exhortation is addressed to them by God himself, inviting them to become more spiritually minded (Isa_55:1-3), and fresh promises are held out to the obedient (Isa_55:3-5). The disobedient are then somewhat sternly exhorted to turn from their evil ways and repent (Isa_55:6, Isa_55:7).

Ho, every one that thirsteth! Though the mass are gross and carnally minded, there will ever be some who have higher aspirations—who hunger and thirst after righteousness" (Mat_5:6), and desire spiritual blessings. These are invited, first of all, to come and partake of the good things provided for them in Messiah's kingdom. Come ye to the waters (on the spiritual symbolism of water, see the homiletics on Isa_44:3, Isa_44:4). Here the "peace" and "righteousness" of the Messianic kingdom (Isa_54:13, Isa_54:14) are especially intended. Our Lord's cry on the last day of the Feast of Tabernacles (Joh_7:7) is clearly an echo of this. Wine and milk. These are not symbols of temporal blessings, as many have thought. "Wine, water, and milk are," as Delitzsch says, "figurative representations of spiritual revival, re-creation, and nourishment." Without money and without price. God's spiritual gifts are freely given to men; they cannot be purchased. Being in their own nature "more precious than rubies," their value transcends human means of payment. They cannot even be earned by man's best works; for man's best works are comprised in his duty to God, and have, therefore, no purchasing power. God may choose to reward them; but if he does it is of his free grace.

The Pulpit Commentary
Wherefore do ye spend money? literally, wherefore do ye weigh silver?-silver being the ordinary currency, and money transactions, in default of a coinage, being by weight (cf. Gen_23:16; Zec_11:12). For that which is not bread; i.e. "for that which has no real value—which cannot sustain you, which will do you no good." The affections of the great mass of the Israelites were set on worldly things, on enriching themselves—adding field to field, and house to house (Isa_5:8). They did not care for spiritual blessings, much less "hunger and thirst" after them. That which satisfieth not. Worldly things can never satisfy the heart, not even the heart of the worldly. "What fruit had ye then in those things," says St. Paul, "whereof ye are now ashamed?" (Rom_6:21). Hearken diligently unto me; rather, hearken, oh, hearken unto me. The phrase is one of earnest exhortation. It implies the strong disinclination of Israel to listen, and seeks to overcome it (compare the opening words of the next verse). Let your soul delight itself in fatness (comp. Psa_36:8; Psa_63:5; and Isa_25:6). The spiritual blessings of the Messianic kingdom are richer dainties than any that this world has to offer. The soul that obtains them "delights" in them, and is satisfied with them (Psa_17:15).

The Pulpit Commentary
Come unto me (comp. Isa_55:1, "Come ye to the waters"). God dispenses the waters (see Isa_44:3). I will make an everlasting covenant with you. That the "everlasting covenant" once made between God and man had been broken by man, and by Israel especially, is a part of the teaching contained in the earlier portion of Isaiah (Isa_24:5). We find the same asserted in the prophecies of his contemporary, Hosea (Hos_6:7). It would naturally follow from this that, unless God gave up man altogether, he would enter into a new covenant with him. Accordingly, this new covenant is announced, both in Hosea (Hos_2:18-20) and in the later chapters of Isaiah, repeatedly (Isa_42:6; Isa_49:8; Isa_54:10; Isa_4:3; Isa_56:4, Isa_56:6; Isa_54:1-17 :21; Isa_61:8). Having been thus set before the nation, it is further enlarged upon by Jeremiah (Jer_31:31-33; Jer_32:40; Jer_11:5) and Ezekiel (Eze_16:60-62; Eze_34:25; Eze_37:26-28). Almost all commentators allow that the Christian covenant is intended—that "new covenant" (Heb_9:15) under which man obtains pardon and salvation through the Mediatorship of Christ. Even the sure mercies of David. The "sure mercies of David" are the loving and merciful promises which God made to him. These included the promise that the Messiah should come of his seed, and sit on his throne, and establish an everlasting kingdom (Psa_89:2-5, Psa_89:19-37), and triumph over death and hell (Psa_16:9, Psa_16:10), and give peace and happiness to Israel (Psa_132:15-18). The promises made to David, rightly understood, involve all the essential points of the Christian covenant.

The Pulpit Commentary
Behold, I have given him for a witness. By ordinary rules of grammar, the pronoun "him" should refer to David; and so the passage is understood by Gesenius, Maurer, Hitzig, Ewald, Knobel, Delitzsch, and Mr. Cheyne. But, as Isaiah frequently sets aside ordinary grammatical rules, and as the position to the person here spoken of seems too high for the historical David, a large number of commentators, including Vitringa, Michaelis, Dathe, Rosenmuller, Umbreit, and Dr. Kay, consider that the Messiah is intended. It is certainly difficult to see how the historical David could be, at this time and in the future, a "leader and commander to the peoples" who were about to flock into the Messianic kingdom. A witness … a leader and commander. Christ was all these. He "came to bear witness to the truth" (Joh_18:37), and "before Pilate witnessed a good confession" (1Ti_6:13). He "feeds and leads" his people (Rev_7:17), and is the "Commander" under whose banner they serve (2Ti_2:3, 2Ti_2:4). What he is to his people, he is also of the "peoples" generally; for they have been called into his kingdom, People … people; rather, peoples.

The Pulpit Commentary
Thou shalt call a nation that thou knowest not (comp. Psa_18:43). The object of address in this verse appears to be the Messiah. He, at his coming, will "call" into his kingdom "a nation," or rather, "people," with whom he has had no covenant hitherto; and they will readily and gladly obey the call. Thus God's kingdom will be enlarged, and Israel's glory will be increased, Because of the Lord … for he hath glorified thee. The great cause of the attraction will be the "glory" which God the Father has bestowed upon his Son, by raising him from the dead, and exalting him to a seat at his right hand in heaven (Act_2:32-35; Act_3:13-15).

The Pulpit Commentary
Seek ye the Lord. Again the strain changes. The people are once more addressed, but in a tone of reproach. Israel must "seek the Lord" without delay, or the opportunity will be past; God will have withdrawn himself from them. He "will not alway be chiding, neither keepeth he his anger for ever" (Psa_103:9).

The Pulpit Commentary
Let the wicked forsake his way; i.e. his mode of life. A general promise of forgiveness of sin upon repentance and amendment of life was first given to Israel through Solomon (2Ch_7:14). The doctrine is largely preached by the prophets; but is nowhere more distinctly and emphatically laid down than in this place. God's will is to "multiply pardon," if man will only turn to him.

The Pulpit Commentary
A FRESH ASSURANCE or DELIVERANCE FROM BABYLON. Man can scarcely conceive of the deliverance which God designs; but God's thoughts are not as man's (Isa_55:8, Isa_55:9). God's word, once pronounced, is potent to effect its purpose (Isa_55:10, Isa_55:11). Deliverance from Babylon, having been promised, will take place, and will be accompanied by all manner of spiritual blessings (Isa_55:12, Isa_55:13).

Isa_55:8, Isa_55:9

My thoughts are not your thoughts. Though man is made in God's image (Gen_1:27), yet the nature of God in every way infinitely transcends that of man. Both the thoughts and the acts of God surpass man's understanding. Men find it hard to pardon those who have offended them; God can pardon, and "pardon abundantly.'' Men cannot conceive of coming changes, when they pass certain limits. God knows assuredly what changes are approaching, since they are his doing.

As the rain … and the snow. The rain and the snow are God's ministers (Psa_148:8), and go forth from him, just as his word does. They have an appointed work to do, and do not return to him, whose ministers they are, until they have done it. It is best to translate, with Delitzsch and Mr. Cheyne, "As the rain cometh down, and the snow from heaven, and returneth not thither, except it hath watered the earth," etc. The writer is, apparently, aware, as the writer of Ecclesiastes is, that the water which falls from heaven in the shape of rain does return thither again in the shape of vapour (see Ecc_1:7).

The Pulpit Commentary
So shall my word be. God's word is creative. With the utterance the result is achieved. Hence the sublime passage, which even heathenism could admire (Longin; 'De Sublim.,' § 9), "And God said, Let there be light: and there was light" (Gen_1:3). Hence, too, the more general statement, "By the Word of the Lord were the heavens made; and all the host of them by the breath of his mouth" (Psa_33:6; comp. Psa_148:5). But it shall accomplish; rather, unless it has accomplished. There is a mixture of two constructions, "It shall not return void," and "It shall not return unless it has accomplished," etc. It shall prosper. Every word that proceedeth out of the mouth of God has a prosperous course. It is endued with life from God, and (as Delitzsch says) "runs like a swift messenger through nature and the world of man, there to melt the ice, as it were, and here to heal and to save; and it does not return from its course till it has given effect to the will of the Sender. "The special "word" which the prophet has here in mind is the promise, so frequently given, of deliverance from Babylon and return in peace and joy to Palestine. But he carries his teaching beyond the immediate occasion, for the benefit of the people of God in all ages.

The Pulpit Commentary
Ye shall go out with joy, and be led forth with peace (comp. Isa_35:10; Isa_40:9-11; Isa_43:3-6, Isa_43:19-21, etc.). A strong contrast is frequently drawn between the exodus from Babylon and that from Egypt. On the former occasion all was hurry, alarm, disquiet, danger. The later exodus will be accompanied with "peace" and "joy" (see Isa_51:9-16, etc.). (For the fulfilment, see Ezr_1:1-11; Ezr_2:1-70, and Ezr_7:1-28; Ezr_8:1-36.) The mountains and the hills shall break forth before you into singing. All nature shall rejoice at your deliverance, especially the noblest and the grandest parts of nature—"the mountains and the hills." Isaiah's admiration of mountains continually reveals itself throughout the work (Isa_5:25; Isa_13:2, Isa_13:4; Isa_14:25; Isa_22:5; Isa_30:17, Isa_30:25; Isa_34:3; Isa_40:4, Isa_40:9, Isa_40:12; Isa_42:11, Isa_42:15, etc.). It is quite in his manner to speak of nature as bursting forth into singing (Isa_35:2; Isa_44:23; Isa_49:13). All the trees of the field shall clap their hands. The metaphor is not found elsewhere in Isaiah, but appears in Psa_98:8.

The Pulpit Commentary
Instead of the thorn shall come up the fir tree. "Briars and thorns" were to overgrow the unfruitful vineyard, according to Isa_5:6; and to cover the land of God's people, according to Isa_32:13. This would be literally the case to a large extent, while the land was allowed to lie waste. The literal meaning is not, however, the whole meaning, or even the main meaning, here. "Briars and thorns" represent a general state of wretchedness and sin. The "fir" and "myrtle" represent a happy external condition of life, in which men "do righteously." It shall be to the Lord for a name. This "regenerated creation" will show forth the glory of God to mankind at large, and "get him a name" among them (comp. Isa_63:12; Jer_13:11). For an everlasting sign. It will also he to God himself an enduring sign of the covenant of peace which he has made with his people, not to hide his face from them any more, but to have mercy on them "with everlasting kindness" (Isa_54:7-10).