Sahih Muslim 273a
Hudhaifa reported:
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.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى التَّمِيمِيُّ، أَخْبَرَنَا أَبُو خَيْثَمَةَ، عَنِ الأَعْمَشِ، عَنْ شَقِيقٍ، عَنْ حُذَيْفَةَ، قَالَ كُنْتُ مَعَ النَّبِيِّ صلى الله عليه وسلم فَانْتَهَى إِلَى سُبَاطَةِ قَوْمٍ فَبَالَ قَائِمًا فَتَنَحَّيْتُ فَقَالَ ‏
"‏ ادْنُهْ ‏"‏ ‏.‏ فَدَنَوْتُ حَتَّى قُمْتُ عِنْدَ عَقِبَيْهِ فَتَوَضَّأَ فَمَسَحَ عَلَى خُفَّيْهِ ‏.‏