Psalm 137 King James Version
137 By the rivers of Babylon, there we sat down, yea, we wept, when we remembered Zion.
2 We hanged our harps upon the willows in the midst thereof.
3 For there they that carried us away captive required of us a song; and they that wasted us required of us mirth, saying, Sing us one of the songs of Zion.
4 How shall we sing the Lord's song in a strange land?
5 If I forget thee, O Jerusalem, let my right hand forget her cunning.
6 If I do not remember thee, let my tongue cleave to the roof of my mouth; if I prefer not Jerusalem above my chief joy.
7 Remember, O Lord, the children of Edom in the day of Jerusalem; who said, Rase it, rase it, even to the foundation thereof.
8 O daughter of Babylon, who art to be destroyed; happy shall he be, that rewardeth thee as thou hast served us.
9 Happy shall he be, that taketh and dasheth thy little ones against the stones.

Which clues in the psalm suggest that the author is living in exile? Explain.