Mukhtasar Bukhari (Abridged) 469 — How to sit in Tashahhud

Narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that when (his father Abdullah bin Umar, may Allah be pleased with them both) would sit in prayer, he would sit cross-legged. I also sat in the same way. I was young in those days, so (my father) Abdullah bin Umar (may Allah be pleased with them both) forbade me and said that the correct way of prayer is that you should raise your right foot and fold your left. Upon this, I said, "You (i.e., Abdullah bin Umar, may Allah be pleased with them both) also do the same." He replied, "My feet (have become weak and) cannot bear my weight."