Heidegger considered the history of methaphysics as the history of disregarding the Thruth (altheia,disclosedness) and Being. He believed that in this needy time (modern time) paying attention to poetry (poesis) can help us to think of Being. In “Holderlin and the essence of poetry” he regardes poetry (poesis) as the essence of language and all arts. In this work, he investigates the relation between poetry (art) and language and the Holly dimension. Here, he uses five statements of Holderlin poems and explains them. In Heidegger's view, poetry is the most innocent of all occupations that is completely harmless and, at the same time, it is ineffectual. It has nothing about it of action but it is like a dream that connect men to Divine. The language is the field of the most innocent of all occupation and poet through “naming”, play an important role in disclosedness of things. In poetry - that is the essenee of art - beings show themselves as they are. This is the beginning of naming of Divine. Poet through a poetic thinking and preparing himself for openness of divine, begins an authentic dialogue with Divine. Poet, on the bases of this dialogue, can name every thing. Since the field of poetry is language, so the essence of poetry is conceived only through the essence of language, for this is language that names beings or the essence of things. Poetry is the “saying” that, for the first time, names every thing that we say. Then opetry is the first language of a nation and poet stands between earth and God. Poet stands out of everydayness and do the dangrous work for disclossedness of Being. These statements shows the important role of language in Heidegger’s thinking.