Stuck in a rock and a hard place
Kendrick’s referencing the common idiom: Stuck between a rock and a hard place, which means that both situations around the speaker are bad outcomes
Kendrick might be referencing that he doesn’t have a choice between these bad outcomes and he’s living within both
He’s stuck in between the rock and the hard place that all the rap gods are in between — he isn’t getting away from the two. Therefore he has to stay in between and learn how to survive in there with the greats without getting his ass kicked in there.
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