The Messenger of Allah ﷺ said: When any one of you treads with his sandal upon an unclean place, the earth will render it purified. (Using translation from Abū Dāʾūd 385)
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «إِذَا وَطِئَ أَحَدُكُمْ بِنَعْلَيْهِ فِي الْأَذَى فَإِنَّ التُّرَابَ لَهُمَا طَهُورٌ»