all the country: Romans 12:15
the brook: The brook Kidron, which is but a few paces broad, runs along the valley of Jehoshaphat, east of Jerusalem, to the south-west corner of the city, and then, turning to the south-east, empties itself into the Dead Sea. Like the Ilissus, it is dry at least nine months in the year, being only furnished with water in the winter, and after heavy rains. Its bed is narrow and deep, which indicates that it must formerly have been the channel for waters which have found some other, and probably subterraneous course.
Kidron: 1 Kings 2:37; John 18:1, Cedron
the wilderness: 2 Samuel 16:2; Matthew 3:1, Matthew 3:3; Luke 1:80