Nafi' narrates from Ibn Umar (may Allah be pleased with them both) that he said: I saw the Prophet (peace and blessings be upon him) sitting with his knees drawn up (ihtiba') in the courtyard of the Ka'bah, and he (peace and blessings be upon him) was gesturing with his hand. Abu Hatim interlaced his fingers (tashbik).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5914
Abdullah bin Hassan al-Anbari (may Allah have mercy on him) said: My two grandmothers, Safiyyah and Duhaybah, the daughters of Ulaybah (Musa bin Harmalah said: the two of them were raised in the care of Qaylah bint Makhramah (may Allah be pleased with her), and she was their father's grandmother), informed that she saw the Messenger of Allah (peace and blessings be upon him) sitting in the posture of al-qurfusa' (squatting). When I saw the Messenger of Allah (peace and blessings be upon him) (with utmost dignity) (and Musa said: he (peace and blessings be upon him) was humble and lowly in his manner of sitting), I trembled out of awe. Abu Ubayd said: Al-qurfusa' means that a man sits in the manner of one sitting with his knees drawn up (ihtiba'), placing his hands together on his shins, just as one draws up the knees with a cloth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5915
Rubayh bin Abd al-Rahman narrates from his father, from his grandfather Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him), that when the Messenger of Allah (peace and blessings be upon him) sat in a gathering, he would sit with his knees drawn up, holding them with his hands.
Abdullah bin Ibrahim al-Ghifari is alone in narrating it, and he is a shaykh who is munkar al-hadith (his narrations are rejected); Abu Dawud al-Sijistani and others said so.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5916
Sayyiduna Jabir (may Allah be pleased with him) said: I came to the Prophet (peace and blessings be upon him) while he (peace and blessings be upon him) was sitting with his knees drawn up, wrapped in a sheet, and its fringes had fallen over his (peace and blessings be upon him) feet.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5917