I forbid you to know
As ominous means baleful, forbidding, menacing, minacious, and so on, it is not the correct word to use in the sentence.
a sentence using forbidding: the house looked forbidding.
The castle looked forbidding.Why are you forbidding me to drive?I am glad they passed laws forbidding people to smoke in restaurants.
Sure. There are different ways to use forbidding... The haunted house looked forbidding and dark, so Sylvia was afraid to enter. Congress passed a law forbidding the use of certain substances.
The forbidding chapter lead such a curiosity among the students
An example would be "I am forbidding you from going to the party."
Unwelcoming.
A Valediction: Forbidding Mourning is a poem by John Donne.
Walking into the grim, forbidding house, Johnny felt a shiver travel down his spine.
By forbidding American trade at the New Orleans port
An act of forbidding or dissallowing by force.
a conceit