We are now in Perek Shira, the song of the clouds, which is Tehilim 18,12
יָ֤שֶׁת חֹ֨שֶׁךְ ׀ סִתְר֗וֹ סְבִֽיבוֹתָ֥יו סֻכָּת֑וֹ חֶשְׁכַת־מַ֝֗יִם עָבֵ֥י שְׁחָקִֽים׃God uses darkness to be His hiding place. Around Him is a sukkah, the darkness, the waters, and the clouds from the Shahakim (There are seven different heavens, and one of them is called Shahakim.)
Firstly, it says clouds are used to create darkness. Simply speaking, this means that clouds create darkness and clouds are responsible for the rain. Rain comes out of clouds.
The Midrash Rabba in Bereshit 13,10 tells us about rain: Where does the land get its water from? Where does it drink from? Rebbe Eliezer says, from the oceans, as it says in the pasuk, "A cloud comes out from the ground," which is evaporation. Rabbi Yeshua asks, If that's the case, then we should have salty rainwater. Because if the source of rain is the oceans that are salty, then the o rain should be salty too. And his answer is, they become sweet in the clouds. So the song of the clouds is that they impact water.
Additionally, it says Aveh Shehakim, which means to grind. Rav Shimon ben Lakesh says that the clouds grind the water just like in human beings, our stomachs cause the food to become smaller particles, so too the clouds grind the water and turn it into raindrops, which is another important function. So we have two functions here. One is that the clouds sweeten the water. Another is that it comes down in drops, rather than just being poured down in a gush like Niagara Falls. The clouds are impactful in that process. So, again, the song of the clouds, which they're singing to us, is the wonder of creation, and how they are involved in the water cycle, rain and eventually all of growth.
How does this work? Firstly, we have to understand how the water goes up. As we know, when the sun heats the oceans, the water vapor that forms rises to cooler temperatures, because as we know, air rises and condenses as clouds.
Air currents then circulate these clouds around the globe, and the water condenses. The clouds become heavy, and the precipitation is released. That's the water cycle.
This is very important because only 2.5% of the earth's water is fresh water, and of that 2.5% most is frozen. Only 0.001% of the world's water is accessible for drinking. And therefore, without precipitation, there would be no rain, there would be no water, and the whole world would cease to exist! Clouds play a most important part in that process of getting the water up.
And how does it turn into a drop? Way up high in the atmosphere, dust and smoke particles suspended in clouds create places where moisture can settle and form into drops. So they need to land on something. The drops sitting up there are like little globes of water, and they form into shape, stick together and eventually they come down. And all of this happens because of clouds. If the clouds didn't have those particles, we would have no place for the rain to attach and create raindrops.
This is scientifically fascinating. But of course, it's not science, it's God, in His great wisdom, Who created these clouds. And the clouds, which know good and well what's going on, are singing this song- that's on the simple level.
On a deeper level, the Rambam, in his perush Mishnayot on Avot 5,4 tells us that there were ten different miracles in the splitting of the sea. One of them was that when the water split, there were tunnels, and these tunnels were see-through, so that each tribe could see the other. And he quotes our pasuk, חֶשְׁכַת־מַ֝֗יִם עָבֵ֥י שְׁחָקִֽים which refers to the clouds that helped in this process.
So the clouds also sing the song of their involvement in the splitting of the sea.
Finally, the Torat HaMinha from Rav Yaakov Sakili, in derush 83 says, If you take the last letters of חֶשְׁכַת־מַ֝֗יִם עָבֵ֥י שְׁחָקִֽים it spells תמים, which is a hint to Yaakov Avinu, who is called an איש תם, and whose face was etched on the Kiseh HaKavod, surrounded by the clouds.
So there a lot of depth to this pasuk, from the simple meaning of the clouds singing the song of the water cycle to the clouds singing the songs of the splitting of the sea, and the clouds singing the song of being close to the picture of Yaakov Avinu and the Kiseh Hakavod.