the cause of which is, on the one hand, a failure to trace all the routes of the hadith, and on the other, a failure to consider the general hadith of Ibn Umar, may Allah be pleased with him and his father: the Prophet, peace and blessings be upon him, was asked about the night prayer, and he said, “Two by two.” (1)
Accordingly, every hadith that states an unrestricted number of rak'ahs for the night prayer must be understood in light of this hadith, which restricts it to prayers performed two by two.
As for what explicitly indicates otherwise, such as Witr prayed with five, seven, or nine rak'ahs, (2) this serves as an exception to the general meaning of this hadith.
If it is asked: Why did Aisha say, “He would pray four, then pray four”?
The answer is that he performed the first four in one continuous sequence: he prayed two rak'ahs, then immediately followed them with another two; then he sat and rested for a while. He then resumed, praying two rak'ahs and following them with another two; then he again sat and rested for a while. He then prayed three. From this, the early generations understood that they should pray four rak'ahs with two salams, then rest; then pray another four with two salams, then rest; and then pray three, when praying eleven rak'ahs.
His statement, “Twenty rak'ahs”: if the minimum complete form of Witr is added to this, it becomes twenty-three. Thus, one prays twenty rak'ahs of Tarawih, then three rak'ahs of Witr, making a total of twenty-three rak'ahs. This is the night prayer of Ramadan.
The evidence is what Abu Bakr Abd al-Aziz narrated in al-Shafi from Ibn