The Prophet ﷺ used to pray during the night, and when he finished he would say to me, "Get up and pray witr."
حدثنا عبد الرزاق حدثنا معمر عن الأعمش عن تميم بن سلمة عن عروة
كان النبي ﷺ يصلي من الليل فإذا انصرف قال لي قومي فأوتري
Its chain of transmission is sahih. Tamim bin Salama is trustworthy, and his hadith is found in Muslim. The hadith was narrated by Bukhari 1/587 no. 512, and Muslim 1/511 no. 744, both in the Book of Prayer.