Mishnayos Yadayim Perek 2 Mishnah 4

If there was a doubt whether any work has been done with the water or not, a doubt whether the water contains the requisite quantity or not, a doubt whether it is unclean or clean, in these cases the doubt is considered to be clean because they have said in a case of doubt concerning hands as to whether they have become unclean or have conveyed uncleanness or have become clean, they are considered to be clean. Rabbi Yose says: in a case [of doubt as to] whether they have become clean they are considered to be unclean. How so? If his hands were clean and there were two unclean loaves before him and there was a doubt whether he touched them or not; Or if his hands were unclean and there were two clean loaves before him and there was a doubt whether he touched them or not; Or if one of his hands was unclean and the other clean and there were two clean loaves before him and he touched one of them and there was a doubt whether he touched it with the unclean hand or with the clean hand; Or if his hands were clean and there were two loaves before him one of which was unclean and the other clean and he touched one of them and there was a doubt whether he touched the unclean one or the clean one; Or if one of his hands was unclean and the other clean and there were two loaves before him one of which was unclean and the other clean, and he touched both of them, and there is a doubt whether the unclean hand touched the unclean loaf or whether the clean hand touched the clean loaf or whether the clean hand touched the unclean loaf or whether the unclean hand touched the clean loaf The hands remain in the same state as they were before and the loaves remain in the same state as they were before.