Belshazzar's feast, or the story of the writing on the wall, chapter 5 in the Book of Daniel, tells how Belshazzar, acting king of Babylon, holds a great feast. A hand appears and writes burning letters on the wall «Mene, Tekel, Upharsin". The terrified Belshazzar calls for his wise men, but they are unable to read the writing. The queen advises him to send for Daniel, renowned for his wisdom. Daniel reads the Aramic words (Numbered, Weighed, Divided) and interprets it as pointing to the downfall of the Babylonian Empire.

"Here is what these words mean: God has numbered the days of your reign and brought it to an end. You have been weighed on the scales and found wanting. Your kingdom is divided and given to the Medes and Persians” (Daniel 5:26–28)

That very night Belshazzar was killed and his kingdom was conquered and divided.

Now "The writing on the wall" is an idiom that suggests a portent of doom or misfortune

‍