John 14:29

And now I have told you before it come to pass, that, when it is come to pass, ye might believe.
— John 14:29, King James Version

In other translations

World English Bible (WEB)

Now I have told you before it happens so that, when it happens, you may believe.

American Standard Version (ASV)

And now I have told you before it come to pass, that, when it is come to pass, ye may believe.

Young's Literal Translation (YLT)

'And now I have said <FI>it<Fi> to you before it come to pass, that when it may come to pass, ye may believe;