PSALM FORTY-SIX, Verse 4

There is a river the streams whereof shall make glad the city 
 of God, the holy place of the tabernacles of the most High. Psalm 46:4 AV

The psalmist sings of the waters of a river--but there is no river in Jerusalem;
the city draws its water from deep pools and springs ( 2 Kings 20:20 )
 The river is invisible to those who cannot see it,
but to those who have received the revelation of God
( to those to whom it has been revealed)
the life giving river flows every month of the year.
It flows to the East and to the West and it brings life.
In prophecy a river rises in the temple
to give life to the land  (Ezekiel 47:1-12)

ZECHARIAH 14:8
On that day , living waters shall flow from Jerusalem,
half to the eastern sea and half to the western sea,
and it shall be so in summer and in winter.

REVELATION 22:1-2
The angel then showed me the river of life giving water,
clear as crystal, which issued from the throne of God and of the Lamb.
and it flowed down the middle of the streets.