Muwatta Malik Book 6, Hadith 3
Malik related to me from Ibn Shihab from Urwa ibn az-Zubayr that
Abd ar-Rahman ibn Abd al-Qari said, "I went out with Umar ibn
alKhattab in Ramadan to the mosque and the people there were spread
out in groups. Some men were praying by themselves, whilst others were
praying in small groups. Umar said, 'By Allah! It would be better in
my opinion if these people gathered behind one reciter.' So he
gathered them behind Ubayy ibn Kab. Then I went out with him another
night and the people were praying behind their Qur'an reciter. Umar
said, 'How excellent this new way is, but what you miss while you are
asleep is better than what you watch in prayer.' He meant the end of
the night, and people used to watch the beginning of the night in
prayer."
Yahya related to me from Malik from Ibn Shihab from Abu Salama ibn Abd ar-Rahman ibn Awf from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, used to exhort people to watch the night in prayer in Ramadan but never ordered it definitely. He used to say, "Whoever watches the night in prayer in Ramadan with trust and expectancy, will be forgiven all his previous wrong actions."
Ibn Shihab said, "The Messenger of Allah, may Allah bless him and grant him peace, died while that was still the custom, and it continued to be the custom in the caliphate of Abu Bakr and at the beginning of the caliphate of Umar ibn al-Khattab."
Yahya related to me from Malik from Muhammad ibn Yusuf that as- Sa'ib ibn Yazid said, "Umar ibn al-Khattab ordered Ubayy ibn Kab and Tamim ad-Dari to watch the night in prayer with the people for eleven rakas.The reciterof the Qur'an would recite the Mi'in (a group of medium-sized suras) until we would be leaning on our staffs from having stood so long in prayer. And we would not leave until the approach of dawn."