This article explores the moment of “invention” of the Hebrew mood. Around the year 1900 a new expression for mood appeared in Hebrew: matsav ruah. The articulation of a new linguistic expression was paralleled by the rise of an original atmospheric prose, mood prose, in Hebrew. By analyzing these parallel events, the article suggests that the matsav ruah of the early 1900s was a new form of self-experience and that this new form stimulated original poetic language created by a cohort of Hebrew, East European writers, including Yosef Hayim Brenner, Uri Nissan Gnessin, and others. The author suggests that, with mood, Hebrew prose figuratively stretched language itself, giving form to a new sense of “being there.” Furthermore, this poetics of mood offered authors an alternative to psychological realist prose and to the fixed subject position it implied. Thus, this article suggests that Hebrew phrasing and poetics of mood offer a potent concept for the analysis of epistemological foundations of early twentieth-century modernism in Hebrew literature while drawing an outline for a wider, comparative view on early twentieth-century European modernism in light of the concept of mood.