Abdullah bin Abbas reported,

I spent a night at the home of my aunt Maymunah. The Prophet ﷺ got up during the night to perform a voluntary prayer. He went to the waterskin and made ablution, then stood and began to pray. When I saw him do that, I got up, performed ablution from the waterskin, and then stood on his left side. He took my hand from behind his back and moved me around behind him to his right side.I asked, "Did this happen during a voluntary prayer?"He answered, "Yes."

Muslim 1800

Sahih

و حدثني محمد بن حاتم حدثنا محمد بن بكر أخبرنا ابن جريج أخبرني عطاء

عن ابن عباس قال

بت ذات ليلة عند خالتي ميمونة فقام النبي ﷺ يصلي متطوعا من الليل فقام النبي ﷺ إلى القربة فتوضأ فقام فصلى فقمت لما رأيته صنع ذلك فتوضأت من القربة ثم قمت إلى شقه الأيسر فأخذ بيدي من وراء ظهره يعدلني كذلك من وراء ظهره إلى الشق الأيمن قلت أفي التطوع كان ذلك قال نعم

مسلم 1800صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Travelers' prayer and its shortening
Chapter
Supplication in the night prayer and its standing
Numbering
Darussalam 1800
Muslim 1800