there's no telling

there's no telling

Something is unknown because it cannot be predicted. He acts so erratically that there's no telling what he will do next.
See also: no, telling
Farlex Dictionary of Idioms.

there's no telling

It's impossible to determine, as in There's no telling how many children will come down with measles, or There's no telling what will happen in the next episode of that soap opera. This idiom uses telling in the sense of "reckoning," a usage dating from the late 1300s.
See also: no, telling
The American Heritage® Dictionary of Idioms by Christine Ammer.

there's no telling

it's impossible to know what has happened or will happen.
See also: no, telling
Farlex Partner Idioms Dictionary
See also:
  • you're telling me
  • You're telling me!
  • telling
  • say (something) to (one's) face
  • say to face
  • gain (something) by (doing something)
  • gain by doing