What is a phraseological unit? Such ontological questions are usually either avoided altogether or answered away by resorting to an endless recess of ever smaller constituents organised by logical rules, thus unwittingly paving the way for the metaphysics of Universals and Laws of Nature. This article looks into the phraseological questions, which, as known, constitute a part of lexicology and was formed as an independent discipline not long ago. Accordingly, a number of questions pertinent to phraseology have neither been studied nor thoroughly researched. This article endeavors to examine certain phraseologisms existing in scientific circles and study those of religious origin existing in the French language. Considering the presence of books and dictionaries with biblical phraseologies, we decided to research the phraseologisms of Koran origin available in the French language, and their semantic and stylistic properties. In this research, we present examples of phraseologisms registered in the language and those not registered in the dictionaries, which have either been borrowed from Koran or are associated with Koran. The list of expressions in the Koran is not completed. We will continue our research and hope to publish a dictionary of phrases original Koran. This study is very important because the phrases phraseological enrich the language, are more expressive on the other hand, it allows to better understand our history, culture, traditions and customs of the people.