Abu al-Uyuf al-Anazi (may Allah have mercy on him) said: I heard Sayyidah Asma' bint Umays (may Allah be pleased with her) say: I heard the Messenger of Allah (peace and blessings be upon him), with these two ears of mine, say: "Whoever is afflicted by worry, grief, illness or hardship and says: 'Allah is my Lord; He has no partner' - it will be removed from him."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20767