It is narrated from Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) that he said: The Messenger of Allah (peace and blessings be upon him) came to us and placed his blessed foot between me and Fatimah (may Allah be pleased with her), then taught us what we should say when we lie down in bed. He (peace and blessings be upon him) said: "O Fatimah, when the two of you come to your bed, say Subhan Allah 33 times, Alhamdu lillah 33 times and Allahu Akbar 34 times." Sayyiduna Ali (may Allah be pleased with him) said: By Allah, I have never left these words since. A man who had some resentment against Sayyiduna Ali asked: Not even on the night of Siffin? He replied: Yes, not even on the night of Siffin did I leave these glorifications. This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.