Bulugh al-Maram

A’ishah (RAA) narrated, ‘The Messenger of Allah (ﷺ) said to her, “Your Tawaf by the Ka'bah and your Sa'i between Safa and Marwah is sufficient for both your Hajj and 'Umrah (i.e. one Tawaf and one Sa’i are sufficient as she combined Hajj and 'Umrah.)’ Related by Muslim.