Isaiah - Chapter 30
So Bright, You're Gonna Need Shades
G-d says woe to His rebellious children, who take advice, but not from Him, and who appoint rulers over themselves that are not G-d-fearing. Hoshea, the last king of Israel, sent messengers to the Pharaoh in Egypt without G-d's approval; in the end, he was punished by becoming a prisoner of the Assyrians. Thinking that Pharaoh's aid would be better than G-d's is shameful. All of it came to nothing. The Egyptians ended up being no help at all; they are full of pride, but for doing nothing.
Isaiah is now instructed by G-d to write this prophecy on a tablet in front of the people, and it will be for the last day. The people are like disobedient children, refusing to listen to G-d. They refuse to hear what the prophets have to say, preferring to hear only what they wish to hear. They tell the prophets to leave the path they are on, preferring false prophecies.
Therefore, says G-d, because you prefer the false way, this sin will be like a falling wall, whose collapse comes suddenly. G-d will break it like a jug, without pity, there won't be a useful piece remaining. G-d offered salvation, but the people refused it! They preferred to rely on horses to flee, but their pursuers were fast. But G-d will be gracious and have mercy. He metes out justice, then rewards those who rely on Him.
In the future, a nation will dwell in Jerusalem and there will be no need for tears. When G-d hears us, He will respond. At this point, Isaiah says that G-d will give us a small amount of bread and water; this is a strange thing to say in a prophecy that is supposed to be a consolation. Perhaps it means that we are assured of having these things even in the worst of times. Continuing, our "Teacher" (G-d) will no longer be concealed from us; we will have clear instructions as to how to go. The Jews will strip the gold and silver plating off their idols and cast them out like waste matter.
G-d will cause it to rain so that we can plant and there will be plenty of food for our animals. There will be so much rain that, at the time of Gog and Magog (or possibly the fall of Assyria), the mountains will all have streams running on them. The moon will be as bright as the sun is now and the sun will be seven times brighter when G-d heals His people, Israel. (The Radak says the light is a metaphor for our joy.)
G-d, Whose Name was blasphemed by the Assyrians, is coming to fulfill what He said long ago. His "mouth" (metaphorically) is full of fire and anger. He will shake up the nations and lead them to their downfall. The Jews will sing as they do on a festival. G-d will make His voice heard and He will show His might in a display of fire, hail and thunder. Assyria, Israel's oppressor, will be broken by G-d's voice. Wherever G-d takes action against Assyria, it will be accompanied by the sound of musical instruments. Hell is ready for Sancheriv, the king of Assyria; G-d's "breath" burns in it like sulfur. (Radak says that all this is a metaphor for the harsh things that would befall Assyria.)