A fantastic ending: it dismisses all the other folks insulting Jay, not even deigning to mention them by name. The final insult lasts two beats, or half a bar of music

This was shot at a few rappers, mainly Jadakiss and the LOX, with whom Roc-A-Fella had beef with around the same time. This beef involved the R. Kelly Fiesta remix in which Jada and Jay Z had separate features on different versions of the song

This last line also (perhaps purposefully) legitimizes Jay’s two primary opponents in the song as worthy adversaries. By using multiple verses to address Prodigy and Nas, he acknowledges that they are worth his time to attack even as he destroys them.

Don’t discount the wordplay between “bars” and “shots” here either. Jay could throw the entire establishment at them, but doesn’t bother.

If you attack me (verbally or physically), it will backfire and you will be hurt instead. People close to Nas (and Jay) should have told him not to mess with Hova.

Also, a play on the word “bark”, which is the rough exterior of a tree and the idiom “Barking up the wrong tree” can mean for one to take the wrong course of action.

Years later, 50 Cent would advise The Game against beefing with Jay, proof that he is feared by even the most battle-hardened rappers.

This is a not-so-hidden reference to the fact that Jay had an affair with Carmen Bryan, the mother of Nas' first child. Jay hints at this, and threatens to reveal it publicly if Nas should respond.

Eventually, Jay alluded to this even more graphically on “Supa Ugly” with these lines:

I came in your Bentley backseat, skeeted in your Jeep
Left condoms on your baby seat
…
Yes, you was kissing my dick when you was kissing that bitch

Bringing the baby seat into it apparently crossed the line: even Jay’s own mom said the song was in poor taste and Jay actually apologized to Nas.

This line got a direct response from Nas in his reply song “Ether”:

Ask me if I’m trying to kick knowledge?
Nah, I’m trying to kick the shit you need to learn, though
The Ether, the shit that make your soul burn slow

Jay is making fun of Nas’s attempts to portray himself as a prophet or conscious rapper; Jay elaborated on this critque on “Blueprint 2”:

And y'all buy the shit, caught up in the hype
Cause the nigga wear a kufi, it don’t mean that he bright
Cause you don’t understand him, it don’t mean that he nice
It just means you don’t understand all the bullshit that he write

In the movie Belly, Nas played the character “Sincere”, whilst Oliver Grant played the character “Knowledge.”

Two of Nas' albums were subpar (I Am and Nastradamus). For dramatic effect, Hov is underrating It Was Written which is a very good record that doesn’t quite match Illmatic (“that’s one hot album”).

This line can also read “Two of them shits was DUE,” as in “expected” or “doo” as in shitty.

The ‘lame’ ‘fame’ and ‘brain’ are a play on words sampled from the David Bowie song ‘Fame’.

4 albums in 10 years works out to one every 2.5 years, but Jay rounds down to 2, which was still quite a distance between releases back then (and today even).

The source of Jay’s mockery is his own prolific output. During “Heart of the City” off this record, he states:

But the only thing running is numbers fam
Jigga held you down 6 summers; damn, where’s the love?

The Blueprint was his 6th album since 1996, all of them (eventually) going platinum. He would go on to release 2 more in the next two years, both platinum, totaling 8 in 8 years, an unrivaled run.