Used appropriately, "knock the sand out" is an alternative way to tell a guy when he is being a pussy and needs to man-up. Origins of the original phrase "knock the sand out of your vagina..." can be found on an early season episode of South Park. (Cartman speaking to Kyle)
ESPN Reporter: Vince Young is being kept overnight at Vanderbilt medical center, his family and teammates fear he may be suicidal after today's loss and season-ending thumb injury which will need surgery.
Titans fan: Wow, VY... KNOCK THE SAND OUT!!!
Titans fan: Wow, VY... KNOCK THE SAND OUT!!!
by Tennessee_Webster November 23, 2010