Now we know what the the "4" Kendrick Lamar teased this morning is for.

K.Dot just dropped a new track 'The Heart Part 4.'

In it, he seems very angry at another rapper.

“My fans can’t wait for me to son your punk ass and crush your whole lil shit / I’ll Big Pun your punk ass, you a scared lil bitch / “Tip-toeing around my name, nigga ya lame / And when I get at you, homie, don’t you tell me you was just playin.”

"You know what time it is / Ante up, this is here forever / Y’all got till April the 7th to get y’all shit together,” he raps.

Who do you think Kendrick's coming for?