Sayyiduna Ibn Umar (may Allah be pleased with them both) narrates: When the Messenger of Allah (peace and blessings be upon him) came to Makkah, he performed tawaf of the House, seven circuits, prayed two rak'ahs behind the Station, then went out towards al-Safa through the gate by which he used to go out, and then performed sa'i between al-Safa and al-Marwah. (The narrator) Shu'bah said: Ayyub informed me, through Amr bin Dinar, from Ibn Umar (may Allah be pleased with them both), that this is the Sunnah.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13577