The Prophet confirms what we have already observed that the Church would be subject to many troubles and commotions, so that the faithful should not enjoy the common light, but be more miserable than men in general. And he has ever the same object in view, to prepare the faithful to exercise patience, and to remind them that they are not to promise themselves such enjoyments in the holy land, as though they were to be free from the trials of the cross. Lest then they should deceive themselves with vain hopes, he sets before them many evils and many calamities, that they might confidently wait for the aid, of which he had spoken, while immersed in thick darkness, and hardly able to distinguish between day and night. But the rest shall be considered tomorrow.

The light shall not be clear nor dark - Or, more probably, according to the original reading , "In that day there will be no light; the bright ones will contract themselves," as it is said, "The stars shall withdraw their shining."
This is evermore the description of the Day of Judgment, that, in the presence of God who is Light, all earthly light shall grow pale. So Joel had said, "The sun and moon shall be darkened, and the stars shall withdraw their shining" Joel 3:15. And Isaiah, "The moon shall be confounded and the sun ashamed, when the Lord of hosts shall reign in Mount Zion and in Jersalem and before His ancients gloriously" Isaiah 24:23; and, "Behold the day of the Lord cometh, The stars of heaven and the constellations thereof shall not give their light: the sun shall be darkened in his going forth, and the moon shall not cause her light to shine" Isaiah 13:9-10. All know well our Lord's words Matthew 24:29. John, like Zechariah, unites the failure of the heavenly light "with a great earthquake, and the sun became as sackcloth of hair: and the moon become as blood; and the stars of heaven fell upon the earth" Revelation 6:12-13.

The light shall not be clear, nor dark - Metaphorically, there will be a mixture of justice and mercy in all this; or a bright light and darkness. Mercy shall triumph over judgment. There shall be darkness - distress, etc.; but there shall be more light - joy and prosperity - than darkness.

And it shall come to pass in that day,.... Which shall precede the coming of Christ, both his spiritual and personal reign; for what follows will not agree with either state:
that the light shall not be clear nor dark; before the latter day glory it will be a darkish dispensation; not "clear", as in the first times of the Gospel, when the sun of righteousness appeared, and the shadows of the ceremonial law were removed, and the Gospel shone out in the ministry of Christ and his apostles; nor as at the reformation from Popery, when the morning star was given, Revelation 2:28 nor as it will be in the spiritual reign of Christ, when Zion's light will be come, and her watchmen will see eye to eye; when the light of the moon shall be as the light of the sun, and the light of the sun seven fold as the light of seven days; and much less as will be in the kingdom state, when there will be no need of the sun or moon; or in the ultimate glory, when we shall see no more darkly through a glass, but face to face: and yet it will not be "dark", as it was with the Jews under the legal dispensation; and much less as with the Gentiles before the coming of Christ; or as in the dark times of Popery; it will be a sort of a twilight, both with respect to the light of doctrine, and of spiritual joy, comfort, and experience; which is much our case now. Some read the words, "there shall be no light, but cold and frost" (k); it will be a time of great coldness and lukewarmness, with regard to divine and spiritual things; iniquity will abound, and the love of many wax cold, Matthew 24:12.
(k) , , Sept.; "non erit lux, sed frigus et gelu", V. L; so Syr. Ar.; "congelatio", Tigurine version; so Ben Melech; "non erit lux; frigora potius et congelatio; vel non erit lux; frigoribus congelascent, scilicet peccatores", Hiller. de Arcano Kethib & Keri, p. 370.

light . . . not . . . clear . . . dark--JEROME, Chaldee, Syriac, and Septuagint translate, "There shall not be light, but cold and ice"; that is, a day full of horror (Amos 5:18). But the Hebrew for "clear" does not mean "cold," but "precious," "splendid" (compare Job 31:26). CALVIN translates, "The light shall not be clear, but dark" (literally, "condensation," that is, thick mist); like a dark day in which you can hardly distinguish between day and night. English Version accords with Zac 14:7 : "There shall not be altogether light nor altogether darkness," but an intermediate condition in which sorrows shall be mingled with joys.

Complete salvation. - Zac 14:6. "And it will come to pass on that day, there will not be light, the glorious ones will melt away. Zac 14:7. And it will be an only day, which will be known to Jehovah, not day nor night: and it will come to pass, at evening time it will be light." The coming of the Lord will produce a change on the earth. The light of the earth will disappear. The way in which לא יהיה אור is to be understood is indicated more precisely by יקרות יקפאון. These words have been interpreted, however, from time immemorial in very different ways. The difference of gender in the combination of the feminine יקרות with the masculine verb יקפּאוּן, and the rarity with which the two words are met with, have both contributed to produce the keri יקרות וקפּאון, in which יקרות has either been taken as a substantive formation from קרר, or the reading וקרות with Vav cop. has been adopted in the sense of cold, and קפּאון (contraction, rigidity) taken to signify ice. The whole clause has then been either regarded as an antithesis to the preceding one, "It will not be light, but (sc., there will be) cold and ice" (thus Targ., Pesh., Symm., Itala, Luther, and many others); or taken in this sense, "There will not be light, and cold, and ice, i.e., no alternation of light, cold, and ice will occur" (Ewald, Umbr., Bunsen). But there is intolerable harshness in both these views: in the first, on account of the insertion of יהיה without a negation for the purpose of obtaining an antithesis; in the second, because the combination of light, cold, and ice is illogical and unparalleled in the Scriptures, and cannot be justified even by an appeal to Genesis 8:22, since light is no more equivalent to day and night than cold and ice are to frost and heat, or summer and winter. We must therefore follow Hengstenberg, Hofmann, Koehler, and Kliefoth, who prefer the chethib יקפאון, and read it יקפּאוּן, the imperf. kal of קפא. קפא signifies to congeal, or curdle, and is applied in Exodus 15:8 to the heaping up of the waters as it were in solid masses. יקרות, the costly or splendid things are the stars, according to Job 31:26, where the moon is spoken of as יקר הולך, walking in splendour. The words therefore describe the passing away or vanishing of the brightness of the shining stars, answering to the prophetic announcement, that on the day of judgment, sun, moon, and stars will lose their brightness or be turned into darkness (Joel 3:15; Isaiah 13:10; Ezekiel 32:7-8, Matthew 24:29; Revelation 6:12). In Zac 14:7 this day is still more clearly described: first, as solitary in its kind; and secondly, as a marvellous day, on which the light dawns at evening time. The four clauses of this verse contain only two thoughts; each so expressed in two clauses that the second explains the first. יום אחד, unus dies, is not equivalent to tempus non longum (Cocceius, Hengst.), nor to "only one day, not two or more" (Koehler), but solitary in its kind, unparalleled by any other, because no second of the kind ever occurs (for the use of 'echâd in this sense, compare Zac 14:9, Ezekiel 7:5, Song 6:9). It is necessary to take the words in this manner on account of the following clause, "it will be known to the Lord;" i.e., not "it will be singled out by Jehovah in the series of days as the appropriate one" (Hitzig and Koehler), nor "it stands under the supervision and guidance of the Lord, so that it does not come unexpectedly, or interfere with His plans" (Hengstenberg), for neither of these is expressed in נודע; but simply, it is known to the Lord according to its true nature, and therefore is distinguished above all other days. The following definition, "not day and not night," does not mean that "it will form a turbid mixture of day and night, in which there will prevail a mongrel condition of mysterious, horrifying twilight and gloom" (Koehler); but it will resemble neither day nor night, because the lights of heaven, which regulate day and night, lose their brightness, and at evening time there comes not darkness, but light. The order of nature is reversed: the day resembles the night, and the evening brings light. At the time when, according to the natural course of events, the dark night should set in, a bright light will dawn. The words do not actually affirm that the alternation of day and night will cease (Jerome, Neumann, Kliefoth); but this may be inferred from a comparison of Revelation 21:23 and Revelation 21:25.

In that day - While God is fighting with the enemies of his church, the nations that fought against Jerusalem. Nor dark - There shall be some mercy to allay the bitterness of judgment, and some judgment with our mercy.