Leviticus 5:2-3

²Whosoever toucheth any unclean thing, either that which hath been killed by a beast, or died of itself, or any other creeping thing: and forgetteth his uncleanness, he is guilty, and hath offended:

³And if he touch any thing of the uncleanness of man, according to any uncleanness wherewith he is wont to be defiled, and having forgotten it, come afterwards to know it, he shall be guilty of an offence.