Pass Me, teacher

If science was my religion,
Moses would unroll his commandments.
But they would not be a list of laws.
They would be a guide (showing our green).

Just one word. An irregularity.
(And everything should be grammatically correct and proper.)

Answers are cloaked in mystery (it's about being in the right place at the wrong time)
And it's right in front of you (or at least back a few)
Sometimes breaking the rules is acceptable if we do not talk about it..