In ancient Rome, gladiators would fight to please the gods.
The ultimate sign of approval from the gods was a downpour of rain.
Can be interpreted to modern innuendo by referring "bringing the rain" to pleasing your God.
When you call a massive artillery or air strike to a specific target. Came from Technical Sergeant Robert Epps in Transformers when the Army Rangers
were under attack by Scorponok
TSgt Epps - "Spooky 3 2; Use 105 Shells; Bring The Rain."
When you take something seriously and excel as a result.
This usually occurs after you just fuck around for a while (usually intentionally) and perform at merely an average, or below average level. Then when you decide its time to "bring the rain", you take it more seriously and dominate whatever it is your doing - playing basketball, doing an exam, playing playstation etc.
Okay, enough of this fucking around, it's time to bring the rain.
Dude, I don't give a fuck about these practice tests, I'll just bring the rain on exam day.
Escalating one's response to situation with the aim of bringing it to a conclusion.
Statement: "Yo, I'm sick of this shit, time to bring the rain."
Response: "Yeah boy, that rain was brought."
Refers to periods of domination in a ping pong game.
"Oh, yes, that's five points in a row for me". "He just brought the rain" -- paste particle of Bring the Rain