It is narrated from Hazrat Abu Umamah (may Allah be pleased with him) that when the Noble Prophet (peace and blessings be upon him) would begin the night prayer, he would say "Allahu Akbar" three times, "Subhan Allah" three times, and "La ilaha illallah" three times, then he would recite this supplication: "O Allah, I seek refuge in You from the pricks of Satan, his blowing, and his shirk."
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 22177
Hadith Gradingحکم دارالسلام:حسن لغيره، وهذا إسناد ضعيف الإبهام الراوي له عن أبى أمامة، وقوله: وشركه غير محفوظ فى هذا الحديث، والمحفوظ: ونفثه