Amr bin Sulaym al-Zuraqi heard Abu Qatadah (may Allah be pleased with him) say: We were sitting in the mosque when the Messenger of Allah (peace and blessings be upon him) came out to us. He (peace and blessings be upon him) was carrying Umamah bint Abi al-As bin al-Rabi' (may Allah be pleased with her). Her mother was Zaynab (may Allah be pleased with her), the daughter of the Prophet (peace and blessings be upon him), and she was a little girl. He (peace and blessings be upon him) was carrying her on his shoulders and he (peace and blessings be upon him) was leading the prayer. When he (peace and blessings be upon him) bowed, he would put her down on the ground, and when he stood up, he would pick her up again; in this way he (peace and blessings be upon him) completed the prayer. He (peace and blessings be upon him) would do this with the girl.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 613