Levítico 5:3

3 or if they touch human uncleanness (anything that would make them unclean) even though they are unaware of it, but then they learn of it and realize their guilt;

3 Or if he touch the uncleanness of man, whatsoever his uncleanness be wherewith he is unclean, and it be hid from him; when he knoweth of it, then he shall be guilty.