Among linguistic philosophers, speech act theory has illuminated the fact that uttering a sentence does not merely convey information; it may also involve the performing of an action. The concept of communicative action provides additional tools to the exegetical process as it points the interpreter beyond the assumption that the use of language is merely for descriptive purposes. Language can also have performative and self-involving dimensions. Despite their clear hermeneutical importance, the notions expressed within speech act theory have been generally neglected by biblical interpreters. The few who have applied speech act theory to the OT typically subsume the discipline into an eclectic type of literary/rhetorical criticism. Such an approach, though, tends to discount the distinctive notions expressed by theoreticians. This dissertation presents the basic philosophical concepts of speech act theory in order to accurately implement them alongside other interpretive tools. The above analysis leads to applying these concepts to Isaiah 41:21-29, 49:1-6, 50:4-10, and 52:13-53:12. These four sections intricately function within the overall prophetic strategy of chapters 40-55: the call to return or turn to Yahweh. The way these chapters describe the nature of this return is for the reader to forsake sin, acknowledge and confess Yahweh as God alone. The first passage represents the basic concerns of chapters 40-48 and specifically Jacob-Israel's deliverance from Babylon through Yahweh's Cyrus illocutionary act. The final three passages represent the servant leitmotif running throughout the chapters and implore the reader through self-involvement to embrace the role of Yahweh's servant.