Thou hast increased the nation, O LORD, thou hast increased the nation: thou art glorified: thou hadst removed it far unto all the ends of the earth.
Thou hast - prophetic preterite (Isaiah 9:3).
Thou hast removed (it) far (unto) all the ends of the earth - rather, 'thou hast extended far all the borders of the land' (Vitringa). There is no "unto" in the Hebrew, and the parallelism to "thou hast increased the nation" favours this. However, Junius supports the English version thus: 'Isaiah enlarges upon the previous statement as to the truth of God's wonderful judgments toward the Church; for first, in this verse, they had been removed far unto all ends of the earth; then they had been sore pressed with pain (Isaiah 26:16-17); thirdly, they would have been utterly destroyed had not thy Majesty come to their help (Isaiah 26:18-19); and yet, saith the Church, Thou hast by the same operation consulted for thy glory and for my safety.'