Sahl bin Mu'adh bin Anas (may Allah have mercy on him) narrates from his father, Sayyiduna Mu'adh bin Anas (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) sent out a detachment. A woman came and said: O Messenger of Allah! My husband is setting out for jihad with this detachment, and I used to pray along with his prayer, fast along with his fasting and worship along with his worship. So tell me of a deed by which I may attain his deed. He (peace and blessings be upon him) said: "Are you able to stand (in prayer) without slackening, to fast without breaking your fast, and to remember (Allah) without becoming heedless?" She said: O Messenger of Allah! Is anyone able to do that? He (peace and blessings be upon him) said: "Even if you were given the strength for that, by the One in whose hand my soul is, you would not reach a tenth of it."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17574