Sunan An-Nasai, Chapter: The Book of the Masjids

that he heard Abu Qatadah say: "While we were sitting in the Masjid, the Messenger of Allah (saw) came out to us carrying Umamah bint Abi Al-As bin Ar-Rabi, whose mother was Zainab, the daughter of the Messenger of Allah (saw). She was a little girl and he was carrying her. The Messenger of Allah (saw) prayed with her on his shoulder, putting her down when he bowed and picking her up again when he stood up, until he completed his prayer." (Sahih)