From Sahih Bukhari (Hadith 4255):
Narrated Ibn Abi `Aufa:When Allah's Messenger (ﷺ) performed the `Umra (which he performed in the year following the treaty of Al-Hudaibiya) we were screening Allah's Messenger (ﷺ) from the infidels and their boys lest they should harm him
Reference: Bukhari 4255