Ibn 'Umar (May Allah be pleased with them) reported:
I saw Messenger of Allah (ﷺ) sitting in the compound of the Holy Ka'bah, with the thighs against the stomach and arms around his legs.[Al- Bukhari]. (ID)
App reference (ID): Book 5, Hadith 9 (ID)
Arabic/English book reference (ID): Book 5, Hadith 822 (ID)