My father and I is One

"My father and I is One" said Jesus
Please explain the meaning of this phrase and also the origin.

The Bible. John 10:30
King James Version - I and my Father are one.
Explaining the three-in-one of the Christian Trinity would be better left to a theologian.

I'd like to know which version of the Book of John has that sentence: "My father and I is One." It's hard to imagine who would believe that that sentence is grammatically correct.
SS

As for the question of the origin of a saying attributed to Jesus, the obvious answer is that Jesus said it. If it's in the Book of John, however, that may not be a correct answer. John is the least well authenticated of the Gospels. It attributes many sentences to Jesus that he probably never spoke. ~rb