There are something like 12 (maybe even more) samples in that song. It's the reason it's taken for ever to be released, as they had to get clearance to use them all. You may want to be a little more specific about which sample you mean.
I can't seem to find a full (or, indeed, any) list of samples, but what comes up over and over is that fact that the "main" sample is Faith Evans' "Love Like This".
If you are talking about the sample :
Engine, Engine, Number Nine,
On the New York transit line,
If my train goes off the track,
Pick it up! Pick it up! Pick it up!
Then thats by Balck Sheep and the song is called 'The choice is yours' its from early 90s.