Amir-ul-Momineen (asws) replied when he (asws) was asked, ‘Where do the clouds come from?’ He (asws) as said: ‘They are on the dense trees, on the dunes, and on the shores which are a resort for them. So if Allah (azwj) Mighty and Majestic Intends to Send a wind which stirs them, and Allocates Angels to these who strike it by ‘Al-makhareeq’, and it is the lightning. So they rise up’. Then he (asws) recited this verse: “[35:9] And Allah is He Who sends the winds so they raise a cloud, then We drive it on to a dead country, and therewith We give life to the earth after its death”, the Verse. And the Angel, its name is ‘Al-Ra’ad’ (The Thunder)’.