Sayyiduna Abu Fatimah al-Damri (may Allah be pleased with him) said: I said: O Messenger of Allah, tell me of a deed on which I may remain steadfast and keep doing. He (peace and blessings be upon him) said: "Hold fast to jihad in the path of Allah, for there is no deed like it." I said: O Messenger of Allah, tell me of another deed on which I may remain steadfast and keep doing. He (peace and blessings be upon him) said: "Hold fast to emigration (hijrah), for there is nothing like it." I said: O Messenger of Allah, tell me of another deed on which I may remain steadfast and keep doing. He (peace and blessings be upon him) said: "Hold fast to prostration, for you do not prostrate a single prostration to Allah except that Allah raises you a degree by it and removes a sin by it."
Hadith Referenceالمعجم الكبير للطبراني / مسند من يعرف بالكنى / 19012