"In that day, a man will keep alive a young cow and two goats. And because of the abundance of milk they give, he will have curds to eat. All who remain in the land will eat curds and honey." NIV translation
When God brings judgement from the king of Assyria, He says that the people that are left will eat curds and honey. Curds are things that form as milk sours and honey is a symbol of delight throughout the Bible. The people are going to eat these curds (soured milk) and be very happy to have them. They will go from the abundance of God's provision to being happy with soured milk.
"In that day, in every place where there were a thousand vines worth a thousand silver shekels, there will be only briers and thorns." NIV translation
The vineyards will be overgrown with briers when God brings this judgement on Israel. Their riches will be removed.
"Men will go there with bow and arrow, for the land will be covered with briers and thorns. As for all the hills once cultivated by the hoe, you will no longer go there for fear of the briers and thorns; they will become places where cattle are turned loose and sheep run." NIV translation
Isaiah completes the description of the land after God removes His blessing from Israel. The people that are left will have to hunt instead of growing food.