Narrated Abdullah ibn Khubayb: We went out one rainy and intensely dark night to look for the Messenger of Allah ﷺ to lead us in prayer, and when we found him, he asked: Have you prayed?, but I did not say anything. So he said: Say, but I did not say anything. He again said: Say, but I did not say anything. He then said: Say. So I said: What am I to say? He said: Say: "Say, He is Allah, One, " and al-Mu'awwadhatan thirty three times in the morning and evening; they will serve you for every purpose.
Hadith Referenceسنن ابي داود / أبواب النوم / 5082
Hadith Gradingالألبانی:حسن | زبیر علی زئی:إسناده حسن, مشكوة المصابيح (2163), أخرجه الترمذي (3575 وسنده حسن) ورواه النسائي (5430 وسنده حسن) أبو أسيد ھو أسيد بن أبي أسيد