Question on how to make Wudoo?

[Jalal~]

Assalamu alaikum
i have a question pertaining to wudoo, i understand how to make it (ive been doing it for about 8 years now) and i know we have to clean the ears. But according to this hadeeth about wudu, it doesnt say anything about cleaning the ears:
"narrated by Humraan the freed slave of ‘Uthmaan, who said that ‘Uthmaan ibn ‘Affaan (may Allaah be pleased with him) called for water to do wudoo’. He washed his hands three times, then he rinsed his mouth and nose, then he washed his face three times, then he washed his right arm up to the elbow three times, then he washed his left arm likewise. Then he wiped his head, then he washed his right foot up to the ankle three times, then he washed his left foot likewise. Then he said, “I saw the Messenger of Allaah (peace and blessings of Allaah be upon him) doing wudoo’ as I have done it, then the Messenger of Allaah (peace and blessings of Allaah be upon him) said, ‘Whoever does wudoo’ as I have done it, then prays two rak’ahs in which he focuses completely on his prayer, his previous sins will be forgiven.’” (Narrated by Muslim, al-Tahaarah, 331)"
So why do so many Muslims clean the ears, when in this hadeeth it does not mention ears specifically? Please inform me in a kind way, i am just a curious Muslim, and many Non-Muslims at school ask me about Islam, so i want to be able to provide an answer, and not just say "Well this is what my parents taught me"
I want to have a reason for following my religion, not just blind faith.
Jazakallah Khair.

[Anas Hasan]

According to Hanbali sect they have considered the ears as part of the head, so cleaning the ears is a must (fard).
but the majority of scholars said it's Sunnah mostahabba.

btw, there is another hadeeth about wudoo, in al-Tirmidhi (36) and Nasaa'i (102).

[al yunan]

Assalamu Alaikum brother,
As the other brother explained is a Sunnah. I think you should find a complete book on Wudu and Ghusl and not follow what you read here or there. If you follow a particular Madhab find out it's rulings. Tahara is of paramount importance and should be understood in it's entirety as it may invalidate your Ibada. A relevant Hadith "Cleanliness is the key to Solat and Solat is the key to paradise"
Masalam