From Sahih Bukhari (Hadith 5919):
Narrated Ibn `Abbas:Once I stayed overnight in the house of my aunt Maimuna bint Al-Harith and Allah's Messenger (ﷺ) was with her as it was her turn. Allah's Messenger (ﷺ) got up to offer the night prayer. I stood on his left but he took hold of my two locks of hair and made me stand on his right. Narrated Abu Bishr: (the above Hadith) but he quoted: Ibn `Abbas said, (took hold of) my two braids on my head
Reference: Bukhari 5919