Two fundamental experiences of Yahweh in the Old Testament are an encounter with the 'word' of Yahweh and an encounter with the 'spirit' or 'wind' or 'breath' (rüah) of Yahweh. This thesis explores 'word', ruah, and their relationship in the book of Ezekiel. It argues that the relationship between Yahweh's rüah and Yahweh's word is to be understood not so much in terms of the inspiration and authentication of the prophet but in terms of the transformation of the book's addressees. According to the dominant paradigm for explaining the emphasis on ruah and its relation to Yahweh's word within the book of Ezekiel, the prophet Ezekiel is recovering from the pre-classical prophets, or even pioneering, an emphasis on ruah in prophecy that is conspicuously absent from the classical, writing prophets. This reading interprets the emphasis on ruah in Ezekiel in terms of the self-authentication of the ministry of the prophet. This thesis examines the relationship between ruah and prophecy in Ezekiel and in the rest of the Old Testament, and shows that the dominant paradigm requires modification. The emphasis on Yahweh's ruah in Ezekiel, even the 'prophetic spirit', is best understood in relation to the book's concern for the transformation of its addressees. The prophet Ezekiel's experience of Yahweh's ruah and his own obedience to Yahweh's call are clearly contrasted with the disobedience of the prophet's addressees in order to present Ezekiel as a model for the addressees of the book. His experience illuminates for them how the dramatic vision of the future can become a reality in their experience. This provides a different perspective on the conundrum of the presence in the book of calls to repentance alongside declarations of Yahweh's unilateral salvific actions. Further, it provides an integrated account of the different occurrences of ruah in relation to the rhetorical function of the book. Yahweh's ruah has a fundamental role in the envisaged obedient response to Yahweh's word, both of Ezekiel and of the book's addressees.