Jacob was dying. He was an old, old man. And he gathered all 12 of his sons to him, and he wanted to bless them, or to at least tell them what would happen to their peoples way off in the future. Obviously, God inspired him to do this. It is not something that we necessarily do today. But, Jacob was not only a patriarch, but he was prophet too. And, God gave him these things to tell his sons.
The terms are used for the first time in a very interesting place, Genesis 49:1 where Jacob called his sons together, and said to them, "I'm going tell you what your tribes and nations are going to look like in the last days." And, then he proceeded to tell them all these characteristics so that we in this audience could tell where they are.
Verse 1 gives the general subject of the entire chapter: "that which shall befall you [the children of Israel] in the last days." We will pick up on one of them in verse 16—the tribe of Dan.