In a pine box with nine shots from my Glock, fellas
Pinbox = Casket/coffin. He is going to put Jay Z in a coffin with 9 shots in his body from Nas Glocks. Could also be metaphorically that his words are his bullets and he his killing him with this song.
Here with continueing to rhyme the same word over and over again (fellas) Nas imitates the characteristic rhyming style of Jay-Z associate Beanie Siegel. A subliminal diss.
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