Chapter 28 returns us to the prophecies of First Isaiah. The oracles in today's portion date from the time of King Hezekiah of Judah.
The argument of chapter 28 seems to go like this: The rulers of Israel (called Ephraim here) are condemned as self-serving gluttons and drunkards. (verses 1-6) Samaria, the capital of Israel fell to the Assyrians. Jerusalem's leaders are no better. The priests and prophets mock Isaiah as a speaker of gibberish (verses 9-10). The prophet turns their mockery back against them (verses 11-13) and proclaims YHWH's judgment (verses 14-22). Jerusalem's leaders have made a covenant with death but the city will stand by YHWH's power and grace. Like a farmer, YHWH uses the necessary techniques in judicious measure to bring about the desired results (verses 23-29).
The image of the foundation stone in Isaiah 28:15 was applied to Jesus in the New Testament (Matthew 21:42, Acts 4:11, 1 Peter 2:6-8)
See, I lay a stone in Zion, a tested stone,
a precious cornerstone for a sure foundation;
the one who relies on it
will never be stricken with panic.
Trusting in YHWH and establishing justice are hallmarks of Isaiah's preaching.
Chapter 29 begins with an oracle about Jerusalem, here called "Ariel." According to the Jewish Study Bible this Hebrew word can mean either "hearth of God" (i.e. an altar) or "lion of God." A textual footnote in the New Revised Standard Version suggests the former which, in context makes good sense. The New International Version translates "Ariel" as "altar hearth" at Isaiah 29:2. The translation is interpretive but not unjustified.
The gist of the oracle seems to be that Jerusalem will be besieged and punished but, finally, spared.
Verses 9-14 declare that YHWH has metaphorically blinded, that is confused the prophets. These prophets, we must assume do not include Isaiah. The reason: worship without corresponding ethical action. The result: YHWH will do something surprising. What might that be? Isaiah doesn't say. Why spoil the surprise.
Verses 15-24 proclaim bad news to those who fail to subject themselves to YHWH but promise good news to those who are humbled by circumstance, the meek and poor. Good news for the poor and a concern for social justice are common concerns for the biblical prophets.
Chapter 30:1-18 is an oracle occasioned by Hezekiah's rebellion against his Assyrian overlords. Hezekiah refused to pay tribute and sought aid from Egypt. According to Isaiah, YHWH did not think this was a good idea. Still, YHWH stood ready to forgive (verse 18),
Verses 19-25 are a prose section expanding on the idea of forgiveness. It promises blessings for repentance. The reference to towers falling in verse 25 is not clear to me.
Verses 27-33 pronounce judgment against the Assyrians.
Scripture quotes are taken from the New International Version.
Next: Isaiah 31-35