Abdullah ibn Abu Qays reported that he asked Sayyidah Aisha (RA) about the Witr Salah of the Prophet (SAW). "How he offered the Witr, in the first part of the night or the last part of it? She said, "He offered at each of these hours, sometimes he prayed the witr in the beginning of the night and sometimes at the end of it." Abdullah said, "All praise belongs to Allah who allowed latitude in religion." He asked, "How was his recital? Did he recite softly or audibly?" She said, "He observed each of those. Sometimes he recited in a low voice and sometimes in a loud voice." He said, "All praise belongs to Allah who allowed latitude in religion." He then asked, "How did he act when defiled? Did he havbe a bath before he went to sleep or did he sleep before having a bath? She said, "He did each of these things. Sometimes he had a bath and then slept and sometimes he made ablution and slept." He said, All praise belongs to Allah who allowed latitude in religion."
[Muslim 307, Abu Dawud 1435]