Leviticus 5:3

or if he touches human uncleanness , of whatever sort the uncleanness may be with which one becomes unclean , and it is hidden from him, when he comes to know it, and realizes his guilt ;

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;

Or if he touch the uncleanness of man, whatsoever uncleanness it be that a man shall be defiled withal, and it be hid from him; when he knoweth of it , then he shall be guilty.