It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The one who fights in the path of Allah and the one who performs Hajj to the House of Allah are the delegation of Allah; He called them and they answered His call."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13499