I got it hemmed, now you never get the mic back
This verse starts with “freestyle circle at a party” imagery — a lot of rappers standing around, arguing over the microphone.
“Got it hemmed” is probably a restatement of the more common “got it sewn up,” meaning fully under control and closed to outside influences. Usually, a drug dealer or influential neighborhood person is said to have a certain block or area “sewn up,” indicating his total dominance over that zone
But it could also mean that his style is Custom fit so no one else could wear it.
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