I spent a night with my maternal aunt Maimunah. The Messenger of Allah ﷺ came after the evening has come. He asked: Did the boy pray ? She said: Yes. Then he lay down till a part of night had passed as much as Allah willed; he got up, performed ablution and prayed seven or five rak'ahs, observing witr with them. He uttered the salutation only in the last of them.
بِتُّ عِنْدَ خَالَتِي مَيْمُونَةَ فَجَاءَ رَسُولُ اللَّهِ ﷺ بَعْدَ مَا أَمْسَى فَقَالَ أَصَلَّى الْغُلاَمُ قَالُوا نَعَمْ فَاضْطَجَعَ حَتَّى إِذَا مَضَى مِنَ اللَّيْلِ مَا شَاءَ اللَّهُ قَامَ فَتَوَضَّأَ ثُمَّ صَلَّى سَبْعًا أَوْ خَمْسًا أَوْتَرَ بِهِنَّ لَمْ يُسَلِّمْ إِلاَّ فِي آخِرِهِنَّ