سنن النسائي

It was narrated from Ibrahim bin Muhammad Al-Muntashir, from his father, that: He was in the masjid of 'Amr bin Shurahbil and the iqamah for prayer was said, and they were waiting. He came and said: "I was praying witr." Abdullah was asked: "Is there any witr after the adhan?" He said: "Yes, and after the Iqamah." And he narrated that the Prophet (ﷺ) once slept and missed the prayer until the sun had risen, then he prayed.