Musannaf Ibn Abi Shayba 11:261

Jarir narrated to us, from Mansur, from Salim ibn Abi al-Ja'd, from Atiyyah, the freed slave of Banu Amir, from Yazid ibn Bishr al-Saksaki, who said: I came to Medina and entered upon Abdullah ibn Umar. A man from the people of Iraq came to him and said: "O Abdullah ibn Umar, what is the matter with you that you perform Hajj and Umrah while you have abandoned fighting in the way of Allah?" He said: "Woe to you! Indeed, faith is built upon five: that you worship Allah, establish prayer, give Zakat, perform Hajj, and fast Ramadan. That is how the Messenger of Allah, may Allah bless him and grant him peace, told us." Then he said: "And Jihad is good."