The Prophet's Sunna (legal way) for the sitting in the Tashah-hud [in the Salat (prayer)].

Narrated `Abdullah bin `Abdullah:

I saw `Abdullah bin `Umar crossing his legs while sitting in the prayer and I, a mere youngster in those days, did the same. Ibn `Umar forbade me to do so, and said, "The proper way is to keep the right foot propped up and bend the left in the prayer." I said questioningly, "But you are doing so (crossing the legs)." He said, "My feet cannot bear my weight."