question #3 Sahih al-Bukhari 257, Book 5, Hadith 10 : What is the significance of washing specific body parts during the ritual bath in Islamic tradition?

I placed water for the bath of the Prophet. He washed his hands twice or thrice and then poured water
on his left hand and washed his private parts. He rubbed his hands over the earth (and cleaned them),
rinsed his mouth, washed his nose by putting water in it and blowing it out, washed his face and both
forearms and then poured water over his body. Then he withdrew from that place and washed his feet.