Muwatta Malik Book 7, Hadith 28
Malik related to me that Abd ar-Rahman ibn al-Qasim heard his
father al-Qasim ibn Muhammad say, "I have prayed witr after dawn."
Malik said, "Only a person who oversleeps so that he does not
do the witr prays it after dawn. No one should intentionally make his
witr after dawn."
Yahya related to me from Malik that Abd ar-Rahman ibn al-Qasim said, "I heard Abdullah ibn Amir ibn Rabia say, 'I sometimes pray witr while hearing the iqama, or after the break of dawn.' " Abd ar-Rahman was not certain which he said.
Yahya related to me from Malik from Nafi from Abdullah ibn Umar that Hafsa, the wife of the Prophet, may Allah bless him and grant him peace, told him that the Messenger of Allah, may Allah bless him and grant him peace, used to pray two quick rakas when the muadhdhin had finished the adhan for the subh prayer, before the iqama was said for the prayer.