The H in this statement does not stand for hell as one would suspect, but for something much much worse: Hmong. The Hmong are a dirty and ghetto race of people from the mountainous region between Lao and Thailand who are known for their flat faces and pasty white skin, as well as their short stature.
This statement is used in place of "what the hell." Anywhere hell can be used, H can be used as a more versatile, severe alternative.
What the H?... fucking loc
Your knee is on my balls, get the H off me... you fucking loc
Get the H back to your cotton field where you belong... fucking loc