Hadith Q292
وَالدَّلِيلُ عَلَى أَنَّ ذَلِكَ لَا يُوجِبُ غَسْلَ الْخُفِّ وَلَا النَّعْلِ، وَأَنَ تَطْهِيرَهُمَا يَكُونُ بِالْمَشْيِ عَلَى الْأَرْضِ الطَاهِرَةِ بَعْدَهَا
And the explanation of the evidence that stepping on impurity does not make it obligatory to wash the socks and shoes, and their purification will be achieved by walking on clean ground after that (impurity).
Hadith 292
Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace be upon him) said: "When any one of you steps on filth with his socks or shoes, then their purification is with earth." Imam Abu Bakr (may Allah have mercy on him) says that regarding this chapter, the narration of Abu Nasr from Abu Sa'id (may Allah be pleased with him) about the story of two shoes, I have already mentioned in the Book of Prayer.