It is narrated from Sayyiduna Mu'adh bin Anas al-Juhani (may Allah be pleased with him) that a man asked the Messenger of Allah (peace and blessings be upon him): Which of the mujahidin has the greatest reward? He (peace and blessings be upon him) said: "The one of them who remembers Allah the most." He asked: And which of those who fast has the greatest reward with Allah? He (peace and blessings be upon him) said: "The one of them who remembers Allah the most." Then he mentioned prayer, zakah, Hajj and charity, and each time the Messenger of Allah (peace and blessings be upon him) kept saying: "The one of them who remembers Allah the most." So Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) said to Sayyiduna Umar (may Allah be pleased with him): O Abu Hafs! Those who remember Allah have carried off all the good. And the Messenger of Allah (peace and blessings be upon him) said: "Yes, indeed."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17542