This chapter opens with the lilt of joy. The Arabah, or desert plain, has burst into bloom. That day came because Israel was disobedient to God. Now Israel is restored spiritually, and with spiritual restoration comes physical blessing. When judgement is removed, great blessing follows.
Restoration follows repentance, and restoration is accompanied by joy.
If restoration in the physical realm produces joy, how much greater is the prospect of joy for the one who is restored to God's full purpose. Water makes a desert rejoice, but response to the Water of Life assures personal usefulness accompanied by joy. The sorrow of fruitlessness is transformed into joy by obedience. Make me hear joy and gladness that the bones You have broken may rejoice.