Uthman bin 'Asim bin Husayn عثمان بن عاصم بن حصين أبو حصين · The Book on Al-Witr

he asked Aishah about the Witr of the Prophet. She said: "He would perform Witr during all of the night; (either) its beginning, its middle, or its end. So when he died, his Witr ended, during the approachof As-Sahar."