Yahya related to me from Malik that he had heard that A'isha, thewife of the Prophet, may Allah bless him and grant him peace, used tosay, "If someone fears that he will sleep through till the morning,let him pray the witr before he sleeps, and if some one hopes to wakefor the last part of the night, let him delay his witr." (FR)
App reference (FR): Book 7, Hadith 18 (FR)
USC-MSA web (English) reference: Book 7, Hadith 18 (FR)
Arabic reference (FR): Book 7, Hadith 272 (FR)