Reading the writing on the wall

A lot of common expressions come from Bible but we've forgotten the context. For example the expression that someone could read the writing on the wall, meaning that they may have gotten away with being stupid and irresponsible up until now but they can see at least that things are about to change and that they should prepare for that.

The origin is from today's reading from the Book of Daniel:

King Belshazzar gave a great banquet for a thousand of his lords,
with whom he drank.
Under the influence of the wine,
he ordered the gold and silver vessels
which Nebuchadnezzar, his father,
had taken from the temple in Jerusalem,
to be brought in so that the king, his lords,
his wives and his entertainers might drink from them.
When the gold and silver vessels
taken from the house of God in Jerusalem had been brought in,
and while the king, his lords, his wives and his entertainers
were drinking wine from them,
they praised their gods of gold and silver,
bronze and iron, wood and stone.

Suddenly, opposite the lampstand,
the fingers of a human hand appeared,
writing on the plaster of the wall in the king's palace.
When the king saw the wrist and hand that wrote, his face blanched;
his thoughts terrified him, his hip joints shook,
and his knees knocked.

Interestingly, in the original story Belshazzar cannot actually read the writing on the wall but knows enough to find someone to interpret it for him.

Read the whole thing.