What does this song mean ?

there is a song called jerusalem by matisyahu , and he's talking about jerusalem , I don't know what it means , my brother told me and I forgot and so has he do you know what it means ?

Jerusalem

[Chorus]
Jerusalem, if I forget you,
fire not going to come from me tongue.
Jerusalem, if I forget you,
let my right hand forget what it's supposed to do.

In the ancient days, we will return with no delay
Picking up the bounty and the spoils on our way
We've been traveling from state to state
And them don't understand what they say
3,000 years with no place to be
And they want me to give up my milk and honey
Don't you see, it's not about the land or the sea
Not the country but the dwelling of his majesty

[chorus]

Rebuild the temple and the crown of glory
Years gone by, about sixty
Burn in the oven in this century
And the gas tried to choke, but it couldn't choke me
I will not lie down, I will not fall asleep
They come overseas, yes they're trying to be free
Erase the demons out of our memory
Change your name and your identity
Afraid of the truth and our dark history
Why is everybody always chasing we
Cut off the roots of your family tree
Don't you know that's not the way to be

[chorus]

Caught up in these ways, and the worlds gone craze
Don't you know it's just a phase
Case of the Simon says
If I forget the truth then my words won't penetrate
Babylon burning in the place, can't see through the haze
Chop down all of them dirty ways,
That's the price that you pay for selling lies to the youth
No way, not ok, oh no way, not ok, hey
Aint no one going to break my stride
Aint no one going to pull me down
Oh no, I got to keep on moving
Stay alive

[chorus]...

Maybe it can help you!