“Once we found lodging in a place. Between this place and the Masjid there were dirty passageways. I visited abu ‘Abd Allah (a.s.). He (the Imam) asked, ‘Where have you found lodging?’ I replied, ‘It is the house of so and so.’ He (the Imam) or we said, ‘Between that house and Masjid there are unclean passageways.’ He (the Imam) said, ‘It is not harmful, certain parts of earth cleanse other parts.’ I (the narrator) asked, ‘What happens if I step on wet dung?’ He (the Imam) said, ‘Such things are not harmful.’”