The Messenger of Allah ﷺ was at al-Rawha when he met a group of riders and greeted them.He asked, "Who are you?"They replied, "We are Muslims. And who are you?"They said, "The Messenger of Allah ﷺ."A woman, startled, took hold of a young boy by his upper arm and lifted him out of her covered litter.She asked, "Messenger of Allah, does this child have a valid pilgrimage?"He replied, "Yes, and you will have a reward."
حدثنا أحمد بن حنبل حدثنا سفيان بن عيينة عن إبراهيم بن عقبة عن كريب
كان رسول الله ﷺ بالروحاء فلقي ركبا فسلم عليهم قال من القوم فقالوا المسلمون فقالوا فمن أنتم قالوا رسول الله ﷺ ففزعت امرأة فأخذت بعضد صبي فأخرجته من محفتها قالت يا رسول الله هل لهذا حج قال نعم ولك أجر
Muslim narrated it in Hajj, chapter: The validity of a child's Hajj and the reward of the one who takes him for Hajj, no. 1336, from the hadith of Sufyan bin Uyayna, with this wording, and it is also found in Musnad: 1/219.