Muwatta Malik Book 7, Hadith 6
Yahya related to me from Malik that he had heard that Said ibn
al-Musayyab used to say, "Sleep is disapproved of before isha and
conversation after it."
Yahya related to me from Malik from Zayd ibn Aslam from his father that Umar ibn al-Khattab used to pray as much as Allah willed in the night until at the end of the night he would wake his family for the prayer. He used to say to them, "The prayer, the prayer." Then he would recite the ayat, "Enjoin prayer on your family and be constant in it. We do not ask you for your provision. We provide for you. And the end result is for taqwa." (Sura 20 ayat 132)
Yahya related to me from Malik that he had heard that Abdullah ibn Umar used to say, "(Voluntary) prayer in both the day and night is two at a time with a taslim after every 2 raka'ahs."
Malik said, "That is the custom among us."