The Effective, Fervent Prayer of a Righteous Man

Daniel's personal study of the scriptures reveals that the time of Israel's exile in Babylon is coming to an end, and that soon the Lord will begin to return His people to Jerusalem. Therefore Daniel begins a special season of prayer to that end. But why would Daniel pray for something God had said he was about to do? And what can we learn from this particular specimen of 'effective, fervent prayer?'