Where does “درود” come from?

درود (Persian) comes from Middle Persian drwd, from Old Persian druwatā-, from Old Persian 𐎯𐎢𐎽𐎢𐎺, from Proto-Iranian *druwáh, from Proto-Indo-Iranian dʰruwás, from Proto-Indo-European dʰru-wó-s, from Proto-Indo-European -wós — Creates adjectives from verb stems.

درود (Persian): hello; hi; hail; greeting; health