وعن ابن عمر رضى الله عنهما
قال: رأيت رسول الله صلى الله عليه وسلم بفناء الكعبة محتبياً بيديه هكذا. ووصف بيديه الاحتباء، وهو القرفصاء
I saw Messenger of Allah (sallallahu alayhi wa sallam) sitting in the compound of the Holy Kabah, with the thighs against the stomach and arms around his legs.
Riyad as-Salihin 821, Book 5, The Book of the Etiquette of Sleeping, Lying and Sitting etc, Hadith 9. 1 min read