Synopsis of the Books of the Bible, by John Nelson Darby, [1857-62], at sacred-texts.com
The following commentary covers Chapters 7, 8, and 9:1-7.
But this requires further development; and it is given in a remarkable manner in the next prophecy, comprised in chapters 7, 8, 9 to the end of Verse 7 (Isa 9:1-7). Certain promises were attached to the family of David, in which-as we saw when examining the Books of Samuel-God had renewed the hopes of Israel, when the links between Himself and the people were broken by the taking of the ark, and He had forsaken His place at Shiloh. Now the house of David, the last sustainment of the people in responsibility, has also failed in faithfulness. Ahaz has forsaken Jehovah, and set up the altar of a strange god in the temple of Jehovah. In chapter 7 the Spirit of God directs the prophet to the king, and addresses him. Isaiah was to go and meet him, with Shear-jashub his son-a symbolical child whose name signifies "the remnant shall return." But the Lord seeks first, as He did with respect to the people in chapter 1, to encourage this branch of David to act in faith, and thus to glorify God. He announces to the king that the designs of Rezin and Pekah shall come to nought, and even proposes to him to ask a sign. But Ahaz is too far from the Lord to avail himself of this, though he replies with forms of piety. And again, as He had done with respect to the people, Jehovah declares that which shall happen to the family of David, and to the people under their rule. The two points of this prophetic announcement are-the gift of Immanuel, the virgin's son; and the complete desolation of the land by the Assyrian. These indeed are the keys to the whole prophecy of Isaiah. Nevertheless there shall be a remnant. Verse 16 (Isa 7:16) refers to Shear-jashub; but this prophecy goes farther. In chapter 8 the second prophetic child announces by his name the approaching appearance of this enemy and his ravages; and then, since the people despised the promises made to the family of David and rejoiced in the flesh, Jehovah would take the thing in hand. Consequently we have the whole sequel of the people's history, of the directions given to the remnant, and of God's intervention in power for the establishment of full blessing in the Person of the Messiah.
In chapter 7, where the responsibility of the family of David is the subject, Immanuel is promised as a sign; but the success of the Assyrian is complete without any reverse. Immanuel once brought in, all is changed; the land is His. The Assyrian reaches even to the neck, because the waters of Shiloah had been despised. But Immanuel secured all. Thus the prophetic Spirit passes on to the events of the last days, of which Sennacherib was but a type. He exhibits all the designs and confederacies of the nations brought to nought because of Immanuel-God (is) with us. It is the complete deliverance of Israel in the last days (Isa 8:5-10). And as to the remnant, what course are they to follow? (Isa 8:11, and following.) They are not to be troubled by the fear of the people, nor to join them in their confederacies, but to sanctify Jehovah of hosts Himself, and give Him all His true importance in their hearts. He will be their sanctuary in the day of their trouble.
But who then is this Immanuel, this Jehovah of hosts? We well know. This brings in then the whole history of the rejection of Christ, and the position of the remnant and of the nation in consequence, and of the final intervention of the power of God. The passage is too clear to need much explanation. I will point out its principal subjects. Christ becomes personally a stumbling-stone. [See Note #1] In consequence of this the testimony of God is deposited exclusively in the hands and the hearts of His disciples, God's elect remnant. He hides His face from Jacob; but, according to the Spirit of prophecy, this remnant waits for Him and seeks Him. Meanwhile Christ and the children whom Jehovah has given Him are for signs to the two houses of Israel (compare Rom 11:1-8). Those (the nation) who reject the stone are in rebellion and anguish in Immanuel's land; they are given up to desolation. Nevertheless this distress is not like the former ravages of the Assyrian, because the Messiah, having appeared, has taken in hand the cause of His people, according to the counsels of God. The Spirit of prophecy passes at once, as is constantly the case, from His appearance as light, to the results of the deliverance which He will accomplish in the last days (from Isa 9:2-3). For the church was a mystery hid in God, and not the subject of prophecy or promise. The yoke of the Assyrian being broken, all the brightness of the glory of the divine Person of the Messiah shines out in the blessing of His people.
These two subjects, the Messiah and the Assyrian, form the basis of all the prophecy that speaks of Israel, when this people are the recognised object of God's dealings. It may be noticed that the Assyrian appears here twice-the second time in connection with a gathering together of the nations. The first time, chapter 7, he is Jehovah's instrument for the chastisement of Israel, and he does his own will without any question of his being broken. The second time, chapter 8, he fills the land; but the assembly of the nations gathered together against Israel is broken and brought to nothing. This expectation of Jehovah's intervention (without sharing the fears of the world in the last days, or seeking that strength which the world think to find in confederation, but, on the contrary, resting absolutely on Jehovah alone) contains in principle a valuable instruction for the present day.
[Note: Isa 9:8-21 is discussed in the next chapter.]
The beginning of Verse 17 is the passage quoted in Hebrews 2, along with Verse 18 (Isa 9:17-18), to prove the humanity of the Lord and His connection with the remnant.