question #3 Sahih Muslim 235d, Book 2, Hadith 25 : What is the significance of wiping the head during ablution according to this narration?

This hadith has been narrated by Wuwb on the authority of ‘Amr b. Yahyi with the same chain of transmitters and it has been mentioned therein: He rinsed his mouth. snuffed up water in nostrils and cleaned the nose with three handfuls and wiped his head moving (his hand) in front and then back once. Bahz said: Wuhaib narrated this hadith to me and Wuhaib said: Amr b. Yahya narrated to me this hadith twice.