it is a verse in the holy qura'n {the holy book of the muslims}, in chapter al-rahman, it is repeated many times after mentioning the glory and the benefits of the creation of the almighty Allah, and after each benefit the above phrase is mentioned. the phrase means; how can you deny the glory and the bounties of the almighty allah, you should be thanking him all the time, and you should be worshiping him most of the time.