Muwatta Malik 281

وَحَدَّثَنِي مَالِكٌ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ الْقَاسِمِ، أَنَّهُ سَمِعَ أَبَاهُ الْقَاسِمَ بْنَ مُحَمَّدٍ، يَقُولُ إِنِّي لأُوتِرُ بَعْدَ الْفَجْرِ ‏.‏ قَالَ مَالِكٌ وَإِنَّمَا يُوتِرُ بَعْدَ الْفَجْرِ مَنْ نَامَ عَنِ الْوِتْرِ وَلاَ يَنْبَغِي لأَحَدٍ أَنْ يَتَعَمَّدَ ذَلِكَ حَتَّى يَضَعَ وِتْرَهُ بَعْدَ الْفَجْرِ ‏.‏

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

Reference

Muwatta Malik 281

In-book

Book 7, Hadith 28