It was narrated that Abu Umamah said:
"The Prophet walked on a very hot day towards Baqi' Al-Gharqad (graveyard of Al-Madinah), and the people were walking behind him. When he heard the sound of their shoes, it affected his soul so he sat down until he made them go ahead of him, lest that make him feel too proud." (ID)
English reference (ID): Vol. 1, Book 1, Hadith 245 (ID)
Arabic reference (ID): Book 1, Hadith 253 (ID)