"You have abandoned your people, the house of Jacob. They are full of superstitions from the East; they practice divination like the Philistines and clasp hands with pagans." NIV translation
Isaiah tells us that God left the people to their false gods. He explains how the people started to do the things of the people around them instead of holding to the teachings of God. The "divination" that the verse talks about was the practice of attempting to gain secret knowledge of the future from false gods.
The act of clasping hands symbolizes the agreement to do something as in this case the people started participating in the idolatry of the people that did not know God.
The same holds true today in that, if we start pursuing the ways of the world around us (idolatry), God will not be a part of it. Jesus wants to be the Lord of our lives and that means that he is in control. If we choose to try going in the way of the world, we can no longer be walking with Jesus but, if we repent and turn back to God, he is waiting there to "clasp hands" with us again.
"Their land is full of silver and gold; there is no end to their treasures. Their land is full of horses; there is no end to their chariots. Their land is full of idols; they bow down to the work of their hands, to what their fingers have made." NIV translation
Isaiah continue to list the reasons that God has abandoned the people. He explains that the people and their land has prospered thanks to God but now the people worship the things created instead of the Creator. Material objects have become a god to them and God does not share his divinity.
This passage could describe much of the world today as we have become so proud of the things we possess. The "full of silver and gold" is much the same as our retirement accounts and other bank accounts.
The reference to "chariots" is much like the cars we possess where, in most cases in the USA, families own more than one and treat them as their pride and joy.
"So man will be brought low and mankind humbled- do not forgive them." NIV translation
This verse seems kind of harsh as if Isaiah is disgusted. He says that, because of their idolatry, they will be humbled but it is as if he is asking God to not forgive them. At first glance, we may judge Isaiah harshly but have you ever got so frustrated that you are just disgusted with someone? Isaiah has the burden of seeing what things could be like, if the people turned back to God, and at the same time seeing the reality of a people that do not see a need for repentance. Do you know someone who is content in their sin? That is the situation Isaiah is dealing with and it can be very frustrating.
"Go into the rocks, hide in the ground from dread of the Lord and the splendor of his majesty!" NIV translation
Although Isaiah knows that it is impossible, he now tells the people to try to hide from the coming judgment of the Lord. What is also interesting about this verse is that it describes what is going to happen on the day of the Lord. In Revelation 6:15 & 16, John tells of this happening on that day.
"The eyes of the arrogant man will be humbled and the pride of men brought low; the Lord alone will be exalted in that day. The Lord Almighty has a day in store for all the proud and lofty, for all that is exalted (and they will be humbled), for all the cedars of Lebanon, tall and lofty, and all the oaks of Bashan, for all the towering mountains and all the high hills, for every lofty tower and every fortified wall, for every trading ship and every stately vessel. The arrogance of man will be brought low and the pride of men humbled; the Lord alone will be exalted in that day, and the idols will totally disappear." NIV translation
Isaiah is telling the people that all the material things around them that they take pride in are going to be destroyed. He is once again asking the people to humble themselves willingly. This passage seems even more relevant to our world today as we have all the marvelous things that people have made and we take pride in owning them. From fancy cars to homes to even the latest mobile phone, these things too shall pass away as Isaiah says. Mankind must stop the worship of man made objects and turn back to God (humble ourselves) because, on that day, the Creator is going to be exalted and not the creation.