Leyline of Sanctity and Intuition

[(nameless one)]

Alright, I have a Leyline of Sanctity in the field and my opponent decides to play Intuition, what exactly happens?

Does Intuition get countered or is he even allowed to play Inuition?

Thanks in advance!

[cdr]

Intuition says "target". You are not a legal target. Attempts to play spells or abilities that are not legal are reversed.