It is narrated from Sayyiduna Buraydah (may Allah be pleased with him) that Sayyiduna Khalid bin al-Walid (may Allah be pleased with him) complained to the Messenger of Allah (peace and blessings be upon him) of sleeplessness at night, so the Messenger of Allah (peace and blessings be upon him) said to him: "When you go to your bed, say: 'Allahumma Rabb al-samawat al-sab'i wa ma azallat, wa Rabb al-aradin al-sab'i wa ma aqallat, wa Rabb al-riyahi wa ma adhrat, kun li jaran min sharri khalqik' (O Allah, Lord of the seven heavens and all that they shade, Lord of the seven earths and all that they carry, and Lord of the winds and all that they scatter, be my protector from the evil of Your creation)."
Only al-Hakam bin Zuhayr (may Allah have mercy on him) narrated this hadith from Alqamah (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الألف / 146
Hadith Gradingمحدثین:إسناده ضعيف، تفرد به الحكم بن ظهير وعامة أحاديثه غير محفوظة
Hadith Takhrij«قال ابن عدي: لا يحدث به إلا الحكم بن ظهير عن علقمة بن مرثد والحكم عامة أحاديثه غير محفوظة «الكامل في الضعفاء، ج 2، ص 495»» «أخرجه الترمذي فى «جامعه» برقم: 3523»