Isaiah 9:1-2 [2-3]
Verses 1-6 [2-7] comprise a prophetic poem that brings the section 6:1-9:6 to a close. On the introductory verse in 8:23 [9:1], cf. the previous note; this verse establishes the context for the poem, framing it as a message of hope for the conquered Northern Kingdom of Israel.
Verse 1 
“The people walking in darkness
have seen a great light;
(for those) sitting in a land of death’s shadow
a light has shone upon them.”
The poem begins with a pair of 3-beat (3+3) couplets, which are clearly in parallel (synonymous parallelism). The darkness/light motif was established in the introductory verse (8:23 [9:1], cf. the previous note), as well as at the conclusion of the prior oracle (8:22). In this respect, 8:23 is transitional between the oracle in 8:19-22 and the poem in 9:1ff. In the poem, the darkness of the earlier judgment-oracle gives way to a new message of hope. The people “walking in darkness,” based on the context of the section (and specified in 8:23), are the people of the Northern Kingdom of Israel. Parts of Israel were annexed by Assyria, following the conquests of 734-732 B.C., and turned into Assyrian provinces. A ‘remnant’ of this kingdom persisted for another decade, until the fall of Samaria in 722/721.
The dual motif of “walking” (vb El^h*) and “sitting” (bv^y`, i.e. dwelling, remaining) in darkness is all too appropriate as a figurative description of the Israelite survivors and exiles. In the second couplet, the general image of “darkness” (Ev#j)) is described even more dramatically (and tragically) as “death’s shadow” (“shadow of death,” tw#m*l=x^). The contrast with darkness, naturally enough, is light (roa). Light shines (vb Hg^n`) on this devastated people, bringing hope of salvation and restoration. This Isaian light-theme (2:5; 10:17; 13:10; 26:19; 30:26, etc) will be developed further in the Deutero- (and Trito-)Isaian poems, applying the message of the 8th century oracles to the situation of Judah’s exile (and eventual return) in the 6th century—cf. 42:6, 16; 49:6; 51:4; 58:8ff; 60:1-3ff, 19-20, etc.
Verse 2 
“You multiplied the(ir) rejoicing,
you made great the(ir) joy—
they have joy before you,
as (the) joy in the harvest,
as when (men) circle (in joy)
in their dividing (the) plunder!”
Textual Note: With most commentators, I read hl*yG!h^ (“the rejoicing”) in line 1, rather than MT (also in 1QIsaa) al) yoGh^ (“the nation / not…”).
The meter in verse 3 shifts, from a pair of 3-beat couplets, to a trio of 2-beat (2+2) couplets.
The light that shines upon the people produces an experience of joy. Two parallel roots are used to express this. The first (lines 1 and 5) is lyG], which literally means “to (move in a) circle”, i.e., to dance and circle around joyfully. The second (lines 2-4) is jm^c*, which refers more generally to a feeling of gladness and joy. Two illustrative images are then used to depict the joy that these people feel: (a) the joy experienced with the coming of the harvest, and (b) the military imagery of victorious soldiers rejoicing when they receive a share of booty/plunder (ll^v*) after the battle.
The perfect tenses of the verb refer to the coming restoration as some which has already taken place; this is not uncommon in Old Testament prophecy, but should be distinguished from use of the precative perfect, more common in the Psalms, where one expresses what one wishes (or expects) to happen as though it has already occurred.