(Imām Bukhārī narrates): Musaddad narrated the hadith to us, he said: Yahya bin Sa'id narrated the hadith to us, from Ubaidullah, he said: Nafi' narrated the hadith to me, from Abdullah, from the Prophet ﷺ, that he said:
Make your last prayer at night Witr.
Reference: Sahih Al Bukhari 998