Sunan an Nasai
1692
Sahih+2

It was narrated from 'Abdullah bin 'Umar that:The Messenger of Allah (ﷺ) said: "Prayer at night is two by two, then when you want to finish, pray one rak'h which will make the total number that you prayed odd

SahihAbu Ghuddah
SahihAl-Albani