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