who said it actually?

Question

you know,there is a saying that starts with:"the moving finger writes and having writ it moves on,.............
I know it is from shakespeare,but which of his character said it and on what occassion to whom.

Answer 1

The Moving Finger writes; and, having writ,
Moves on: nor all your Piety nor Wit
Shall lure it back to cancel half a Line,
Nor all your Tears wash out a Word of it

-- Omar Khayyam

Answer 2

The charachter is Omar Khayyam and its a poem not Shakespeare I think.

Answer 3

http://www.cs.rice.edu/~ssiyer/minstrels/poems/545.html