IDIOMS

you knows it

(idiomatic, dialect, slang) Indicates agreement, approval, encouragement.

Example:   You knows it, bra!
  "What he did to her was wrong." "You knows it, sister!"
1861, Frederick Law Olmsted, The Cotton Kingdom: A Traveller's Observations on Cotton and Slavery, page 187
  Mose would ha rallied, ef eed a been in our ward — ha ! ha ! ha ! — you knows it, Mass Richard !
1984, Brian Richard Mori, Dreams of Flight, page 20
  Buster: (impressed) You'se a cool dude, Butch. / Butch: Hey, you knows it, baby.
2002, Lorian Hemingway, A World Turned Over: A Killer Tornado and the Lives It Changed Forever, page 112
  We welcome you, you knows it. Didn't even need to ask, but it fine all right you did."