question #2 Sahih Muslim 273a, Book 2, Hadith 91 : How does the act of wiping over socks relate to the rules of ablution in Islam?

I was with the Messenger of Allah (ﷺ) when he came to the dumping ground of filth belonging to a particular tribe. He urinated while standing, and I went aside. He (the Holy Prophet) asked me to come near him and I went so near to him that I stood behind his heels. He then performed ablution and wiped over his socks.