Hadhrat Umar's (May Allah be well pleased with him) command for offering 20 Raka’at of Taraweeh
Hadhrat ‘Umar ordered the Imams who led the Salaat to lead the people in 20 Raka’at of Taraweeh. There is a Hadith in Musannaf Ibn Abi Shaiba:
عن يحيى بن سعيد أن عمر بن الخطاب أمر رجلا يصلي بهم عشرين ركعة.
Translation: It has been narrated on the authority of Hadhrat Yahya bin Sa‘eed that Hadhrat Umar (May Allah be well pleased with him) commanded a person to offer 20 Raka’at of Taraweeh. (Musannaf Ibn Abi Shaiba, Vol 2, Pg No: 285, Chapter No: 227, Hadith No: 3; Tuhfatul Ahwazi, Bab Ma Ja'a FI Shahri Ramadhan)