The Arabic word used in Surah fatiha for (worlds/Universe)Is العالمین عالم is singular of this wordAnd in Arabic there are two Plural of 'Alim' word عوالم -عالمین Now Why Allah pak used العالمین not عوالمNow in Arabic one type of plural is regular(جمع سالم) and other is irregular (جمع مکسر)The regular one Ends with ین eena.And irregular have different endings .Now in Arabic The Regular Plural is only used for people or living things (Creatures that posses intellect)Now Allah pak said رب العالمین ؟ Not رب العوالم ؟Why ? Can u solve this puzzle ?