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 58:1REPROOF OF THE JEWS FOR THEIR DEPENDENCE ON MERE OUTWARD FORMS OF WORSHIP. (Isa 58:1-14)
aloud--Hebrew, "with the throat," that is, with full voice, not merely from the lips (Sa1 1:13). Speak loud enough to arrest attention.
my people--the Jews in Isaiah's time, and again in the time of our Lord, more zealous for externals than for inward holiness. ROSENMULLER thinks the reference to be to the Jews in the captivity practising their rites to gain God's favor and a release; and that hence, sacrifices are not mentioned, but only fasting and Sabbath observance, which they could keep though far away from the temple in Jerusalem. The same also applies to their present dispersion, in which they cannot offer sacrifices, but can only show their zeal in fastings, &c. Compare as to our Lord's time, Mat 6:16, Mat 6:23; Luk 18:12.
isa 58:2Put the stop at "ways"; and connect "as a nation that," &c. with what follows; "As a nation that did righteousness," thus answers to, "they ask of Me just judgments" (that is, as a matter of justice due to them, salvation to themselves, and destruction to their enemies); and "forsook not the ordinance of their God," answers to "they desire the drawing near of God" (that God would draw near to exercise those "just judgments" in behalf of them, and against their enemies) [MAURER]. So JEROME, "In the confidence, as it were, of a good conscience, they demand a just judgment, in the language of the saints: Judge me, O Lord, for I have walked in mine integrity." So in Mal 2:17, they affect to be scandalized at the impunity of the wicked, and impugn God's justice [HORSLEY]. Thus, "seek Me daily, and desire (English Version not so well, 'delight') to know My ways," refers to their requiring to know why God delayed so long in helping them. English Version gives a good, though different sense; namely, dispelling the delusion that God would be satisfied with outward observances, while the spirit of the law, was violated and the heart unchanged (Isa 58:3-14; Eze 33:31-32; compare Joh 18:28), scrupulosity side by side with murder. The prophets were the commentators on the law, as their Magna Charta, in its inward spirit and not the mere letter.
isa 58:3Wherefore--the words of the Jews: "Why is it that, when we fast, Thou dost not notice it" (by delivering us)? They think to lay God under obligation to their fasting (Psa 73:13; Mal 3:14).
afflicted . . . soul-- (Lev 16:29).
pleasure--in antithesis to their boast of having "afflicted their soul"; it was only in outward show they really enjoyed themselves. GESENIUS not so well translates, "business."
exact . . . labours--rather, "oppressive labors" [MAURER]. HORSLEY, with Vulgate, translates, "Exact the whole upon your debtors"; those who owe you labor (Neh 5:1-5, Neh 5:8-10, &c.).
isa 58:4ye shall not fast--rather, "ye do not fast at this time, so as to make your voice to be heard on high," that is, in heaven; your aim in fasting is strife, not to gain the ear of God [MAURER] (Kg1 21:9, Kg1 21:12-13). In English Version the sense is, If you wish acceptance with God, ye must not fast as ye now do, to make your voice heard high in strife.
isa 58:5for a man to afflict his soul--The pain felt by abstinence is not the end to be sought, as if it were meritorious; it is of value only in so far as it leads us to amend our ways (Isa 58:6-7).
bow . . . head . . . sackcloth--to affect the outward tokens, so as to "appear to men to fast" (Mat 6:17-18; Kg1 21:27; Est 4:3).
isa 58:6loose . . . bands of wickedness--that is, to dissolve every tie wherewith one has unjustly bound his fellow men (Lev 25:49, &c.). Servitude, a fraudulent contract, &c.
undo . . . heavy burdens--Hebrew, "loose the bands of the yoke."
oppressed--literally, "the broken." The expression, "to let go free," implies that those "broken" with the yoke of slavery, are meant (Neh 5:10-12; Jer 34:9-11, Jer 34:14, Jer 34:16). JEROME interprets it, broken with poverty; bankrupt.
isa 58:7deal--distribute (Job 31:16-21).
cast out--rather, reduced [HORSLEY].
naked . . . cover him-- (Mat 25:36).
hide . . . thyself--means to be strange towards them, and not to relieve them in their poverty (Mat 15:5).
flesh--kindred (Gen 29:14). Also brethren in common descent from Adam, and brethren in Christ (Jam 2:15).
isa 58:8light--emblem of prosperity (Isa 58:10; Job 11:17).
health--literally, a long bandage, applied by surgeons to heal a wound (compare Isa 1:6). Hence restoration from all past calamities.
go before thee--Thy conformity to the divine covenant acts as a leader, conducting thee to peace and prosperity.
glory . . . reward--like the pillar of cloud and fire, the symbol of God's "glory," which went behind Israel, separating them from their Egyptian pursuers (Isa 52:12; Exo 14:19-20).
isa 58:9Then . . . call . . . answer--when sin is renounced (Isa 65:24). When the Lord's call is not hearkened to, He will not hear our "call" (Psa 66:18; Pro 1:24, Pro 1:28; Pro 15:29; Pro 28:9).
putting forth of . . . finger--the finger of scorn pointed at simple-minded godly men. The middle finger was so used by the Romans.
speaking vanity--every injurious speech [LOWTH].
isa 58:10draw out thy soul--"impart of thine own subsistence," or "sustenance" [HORSLEY]. "Soul" is figurative for "that wherewith thou sustainest thy soul," or "life."
light . . . in obscurity--Calamities shall be suddenly succeeded by prosperity (Psa 112:4).
isa 58:11satisfy . . . in drought-- (Isa 41:17-18). Literally, "drought," that is, parched places [MAURER].
make fat--rather, "strengthen" [NOYES]. "Give thee the free use of thy bones" [JEROME], or, "of thy strength" [HORSLEY].
watered garden--an Oriental picture of happiness.
fail not--Hebrew, "deceive not"; as streams that disappoint the caravan which had expected to find water, as formerly, but find it dried up (Job 6:15-17).
isa 58:12they . . . of thee--thy people, the Israelites.
old waste places--the old ruins of Jerusalem (Isa 61:4; Eze 36:33-36).
foundations of many generations--that is, the buildings which had lain in ruins, even to their foundations, for many ages; called in the parallel passage (Isa 61:4), "the former desolations"; and in the preceding clause here, "the old waste places." The literal and spiritual restoration of Israel is meant, which shall produce like blessed results on the Gentile world (Amo 9:11-12; Act 15:16-17).
be called--appropriately: the name truly designating what thou shalt do.
breach--the calamity wherewith God visited Israel for their sin (Isa 30:26; Ch1 15:13).
paths to dwell in--not that the paths were to be dwelt in, but the paths leading to their dwellings were to be restored; "paths, so as to dwell in the land" [MAURER].
isa 58:13(Isa 56:2; Neh 13:15-22). The Sabbath, even under the new dispensation, was to be obligatory (Isa 66:23).
foot--the instrument of motion (compare Pro 4:27); men are not to travel for mere pleasure on the Sabbath (Act 1:12). The Jews were forbidden to travel on it farther than the tabernacle or temple. If thou keep thy foot from going on thy own ways and "doing thy pleasure," &c. (Exo 20:10-11).
my holy day--God claims it as His day; to take it for our pleasure is to rob Him of His own. This is the very way in which the Sabbath is mostly broken; it is made a day of carnal pleasure instead of spiritual "delight."
holy of the Lord--not the predicate, but the subject; "if thou call the holy (day) of Jehovah honorable"; if thou treat it as a day to be honored.
him--or else, it, the Sabbath.
not doing . . . own way--answering to, "turn away thy foot from the Sabbath."
nor finding . . . pleasure--answering to, "doing thy pleasure." "To keep the Sabbath in an idle manner is the sabbath of oxen and asses; to pass it in a jovial manner is the sabbath of the golden calf, when the people sat down to eat and drink, and rose again to play; to keep it in surfeiting and wantonness is the sabbath of Satan, the devil's holiday" [BISHOP ANDREWES].
nor speaking . . . words--answering to, "call Sabbath a delight . . . honorable." Man's "own words" would "call" it a "weariness"; it is the spiritual nature given from above which "calls it a delight" (Amo 8:5; Mal 1:13).
isa 58:14delight . . . in . . . Lord--God rewards in kind, as He punishes in kind. As we "delight" in keeping God's "Sabbath," so God will give us "delight" in Himself (Gen 15:1; Job 22:21-26; Psa 37:4).
ride upon . . . high places--I will make thee supreme lord of the land; the phrase is taken from a conqueror riding in his chariot, and occupying the hills and fastnesses of a country [VITRINGA], (Deu 32:13; Mic 1:3; Hab 3:19). Judea was a land of hills; the idea thus is, "I will restore thee to thine own land" [CALVIN]. The parallel words, "heritage of Jacob," confirm this (Gen 27:28-29; Gen 28:13-15).
mouth of . . . Lord . . . spoken it--a formula to assure men of the fulfilment of any solemn promise which God has made (Isa 40:5).
The reason why Jehovah does not deliver His people, notwithstanding their religious services (Isa 58:3), is not want of power on His part, but because of their sins (Isa 59:1-8); Isa 59:9-15 contain their confession; Isa 59:16-21, the consequent promise of the Messiah.