Mishkat al-Masabih 4 Prayer كتاب الصلاة 683

وَعَنْ زَيْدِ بْنِ أَسْلَمَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَنْ نَامَ عَنْ وَتْرِهِ فَلْيُصَلِّ إِذَا أَصْبَحَ» . رَوَاهُ التِّرْمِذِيُّ مُرْسلا

Zaid b. Aslam reported God’s Messenger as saying, “If any of you oversleeps and misses his witr , he should observe it in the morning.” Tirmidhi transmitted it in mursal form.