Musnad Ahmad 1710

It was narrated from Hafsah the daughter of ‘AbdurRahman bin Abi Bakr, from her father, that the Messenger of Allah (ﷺ) said to ‘Abdur-Rahman: "Put your sister - meaning "A"ishah - behind you on your mount and take her for "Umrah from at-Tan"eem. When you bring her down from the hill, tell her to enter ihram, and it will be an "Umrah that will be accepted by Allah."