The permissibility of performing fewer than eleven rakʿahs:

Someone might say, “If you forbid adding to the number of rakʿahs reported from the Messenger of Allah ﷺ for the night prayer—including the Tarawih—then you must likewise forbid praying fewer than that, for there is no difference between addition and subtraction: both alter the textual evidence.”

The answer is: That would indeed be true, were it not for the fact that both the Prophet’s actions and his words establish that praying fewer than this number is allowed.

As for his practice, ʿAbd Allah ibn Abi Qays related: “I asked ʿA’ishah (may Allah be pleased with her), ‘With how many rakʿahs did the Messenger of Allah ﷺ perform witr?’ She replied, ‘He would perform witr with four and three, six and three, and ten and three; he never performed it with fewer than seven nor with more than—’” ⦗96⦘