I agree Nas probably got it from that song.
I dont really mind them mentioning Pac, especially Nas coz his a legend in his own right. I think its good Pac gets props from rappers coming out today shows they have influence from the man and that cant be a bad thing. I dont like it when rappers mention Pac and then in their own music dont talk about issues Tupac was big on, gives me the impression they're just using his name to make themselves bigger, although many fans mistake that for biting.