I'm hoping that I can borrow
A peace of mind, I'm behind on what's really important
My mind is really distorted, I find nothing but trouble in my life

from Kendrick Lamar – Sing About Me, I'm Dying of Thirst Lyrics on Rap Genius

Meaning

The homophones piece and peace make “borrow a peace of mind” a double entendre.

Dave’s brother is looking for insight and a reminder of what his priorities should be, as he’s caught in the haze of Compton life. He asks to borrow it because he knows the troubling reality of his lifestyle: permanent relief is impossible and an early death is likely.

This is the only hope that Dave’s brother gets to verbalize, as he is cut short the next time he tries to hope for something.

Kendrick also makes use of the homophonic “borrow”/“burrow” — “To dig a hole or tunnel for habitation or refuge” — literally, this expresses Dave’s brother’s wish to dig an escape route from his situation, but figuratively, the idea of going underground has morbid connotations that poetically contribute to the hopelessness being alluded to & foreshadow his death at the verse’s end.

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