‘One day Master Isan Reiyu was asked by a monk, “What is the truth?”
Master Isan said, “Not to have an intentional idea is the truth.”
The monk said, “I cannot understand your words.”
Master Isan said, “It is good to know there is something that cannot be understood.”
The monk said, “In what state can we know that there is something that cannot be understood?”
Master Isan said, “When you are just you – not different from yourself.” (Shinjji Shobogenzo)

I peeked at Daido Loori’s translation of this koan as well, and he has the last line as “It’s just that you are not anyone else,” which may be a little neater.