The practice of Hadhrat Abdullah bin Mas’ud (May Allah be well pleased with him)
In ‘Umdatul Qari, Allama Badruddin ‘Aini has narrated a Hadith on the authority of Imam A‘amash in which it is clearly reported that Hadhrat Abdullah bin Mas‘ud used to lead people in 20 Raka’at of Taraweeh.
عن الأعمش عن زيد بن وهب قال كان عبد الله بن مسعود يصلي لنا في شهر رمضان فينصرف وعليه ليل قال الأعمش كان يصلي عشرين ركعة ويوتر بثلاث-
Translation: Hadhrat A‘amash narrates on the authority of Hadhrat Zaid bin Wahb (May Allah be well pleased with him) that he said: In the month of Ramadhan, Hadhrat Abdullah bin Mas‘ud (May Allah be well pleased with him) used to lead us and Imam A‘amash narrates that he used to lead the people in 20 Raka’at of Taraweeh and 3 Raka’at of Witr.
(Umdatul Qari Sharh Sahih Bukhari, Kitab Ut Taraweeh, Vol 8, Pg No: 246)