Rain does come from the oceans as well as lakes, plants, land surfaces and rivers.
The ocean is the main and primary source of water for rain and the atmosphere.
Around 86 percent of global water evaporation comes from the oceans, which is a key part of the Earth's continuous water cycle.
The way rain works, is the sun heats up the ocean's surface water or other surface water and then turns that liquid water into a water vapor also known as a gas, which leaves the salt behind from the ocean water.
The water vapor then rises into the atmosphere, where it then cools and condenses into tiny liquid water droplets and forms ouds.
Air currents and major ocean currents also act like a conveyor belt, which transports the moisture laden clouds around the globe, toward land and the poles.
Then when the water droplets in the clouds become heavy enough, the water droplets then fall back to Earth as precipitation, which can be rain, snow, sleet etc depending on the temperatures.
All the water that falls from the sky, has been on the ground in oceans, lakes, rivers or even in some plants.
States that are closer to oceans tend to get more rainfall than states that are further away from oceans.
Rain water also results from the Gulf of Mexico as well, which is now called the Gulf of America according to Donald Trump.
I still call it the Gulf of Mexico though.