How should the phrase "to the end of the earth" in Acts 1:8 be interpreted? In this essay, the author wants to show how both the location of the verse in Acts and the background of Isaiah determine its significance. The background can be found in texts denoting the universal extension of salvation, like Isaiah 45:22 or Isaiah 49:6, and the universal joyous announcement of salvation in Isaiah 10, Isaiah 11, and Isaiah 48:20, 62.