Dora Bas Rivka Silver O'H
Jerusalem will rejoice over the downfall of Edom (described in the previous chapter). It will bloom like a flower, singing because of the glory of the Temple and the beauty G-d has given them.
Isaiah encourages the Jews to strengthen others (see the grammatical Rashi on verse 3). Tell those frightened by the troubles preceding the salvation to be brave because G-d is coming to save us. Then the "blind" (from fear) will "see" and the "deaf" (to the words of the prophets) will "hear." Israel, who are now lame, will jump like a deer; Israel, currently muted among the nations, will sing because of G-d's salvation. They will blossom like a desert upon receiving springs of water. Those who long for salvation will be saved - compared to dry places becoming pools of water.
There will be a highway leading to Jerusalem for the "blind," "deaf," "lame" and "mute" described above. Even fools will not get lost on it. Neither our enemies nor wild animals will approach us on this road. The redeemed will return to Jerusalem in song, with the "joy of the world" on their heads. (Rashi says this refers to the ancient joy of the salvation from Egypt.) Happiness and joy will pursue them, while sadness and mourning will run away from them.