question #1 Sahih al-Bukhari 60, Book 3, Hadith 2 : What is the significance of properly performing ablution in Islam?

Once the Prophet (ﷺ) remained behind us in a journey. He joined us while we were performing ablution
for the prayer which was over-due. We were just passing wet hands over our feet (and not washing
them properly) so the Prophet (ﷺ) addressed us in a loud voice and said twice or thrice: “Save your heels
from the fire.”