حَدَّثَنَا إِبْرَاهِيمُ بْنُ أَبِي الْعَبَّاسِ حَدَّثَنَا شَرِيكٌ عَنْ أَبِي إِسْحَاقَ عَنِ الْحَارِثِ عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ كَانَ يُوتِرُ عِنْدَ الْأَذَانِ وَيُصَلِّي الرَّكْعَتَيْنِ عِنْدَ الْإِقَامَةِ
مسند امام احمد بن حنبل · Hadith 659
It was narrated from 'Ali that the Prophet (PBUH) used to pray Witr when the adhart was given and he prayed two rnk'ahs when the iqamah was given.
Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020