Yahya related to me from Malik from Ibn Shihab from Ubaydullahibn Abdullah ibn Utba ibn Masud that Abdullah ibn Abbas said, "Iapproached, riding on a donkey, while the Messenger of Allah, mayAllah bless him and grant him peace, was leading the people in prayerat Mina, and I was, at that time, nearing puberty. I passed in frontof part of the row, dismounted, sent the donkey off to graze, and thenjoined the row, and no one rebuked me for doing so."
USC-MSA web (English) reference: Book 9, Hadith 41
Arabic reference: Book 9, Hadith 370