I eat Ether and breathe acid, weak bastards

from Jay Z (Ft. R. Kelly) – The Best of Both Worlds Lyrics on Rap Genius

Meaning

Hov uses a double entendre on this one.
“Ether” is the famous diss track made by Nas directed at Jay.
Ether is also an organic compounds found in chemistry.

Thus Jay is simply saying he wasn’t ‘wounded’ by Nas Diss track. And not only that, but Diss tracks is what he deals with on a daily and it doesn’t stop him from spitting hot rhymes i.e breathe acid

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