Make it rain
I first heard this statement a few years ago from a friend of mine. One of my friends and I were having a conversation about taking our girlfriends out. Of a sudden, this kid asked us if we were going to make it rain on them girls. I did not understand what he meant by that. I asked him to explain it to me. He said that to make it rain is basically spending money on a girl.
Since then, I too started using the statement to mean that I am taking my girlfriend out. I think Hip-Hop music listeners use this slang more often than anyone else. There is even a song by Fat Joe and Lil Wayne called make it rain. In the video, Lil Wayne and Fat Joe basically have stacks of cash, which they keep throwing at the girls in the video. In essence, I think to make it rain means to spend money on women. I also think it is more of a misogynist talk.
Analysis.
Personally, I have heard this statement being used a couple of times. Particularly, I heard it being used in a song make it rain a song by Fat Joe. I like the way Anthony describes the slang but his description does not seem to coincide with the one given in Mo Urban Dictionary: Ridonkulous Street Slang. In the dictionary, Peckham describes to make it rain as basically having a stack of money in a strip club and throwing it all over women (page 162). Anthonys explanation might not be exactly similar to the one given in the dictionary, but it does not mean it is wrong. That is the nature of folklore. It is always available for grabs. That is why one can find a folk racist joke being performed in a movie and at the same time being used in an advertisement.
I have even heard people use this slang in a sexual context. A friend of mine used it when talking about a pornographic movie he had just watched. He said; Simon made it rain on her. By that, he actually meant that Simon ejaculated all over her. What we are seeing here is that different people to mean different things can use the same phrase. That means; to understand what is being meant, one has to understand the lore used by certain folks. In essence, one has to be in that folk group.
Annotation: Make it rain. Mo Urban Dictionary: Ridonkulous Street Slang. First ed. 2007.